Chitosan: An Update on Potential Biomedical and Pharmaceutical Applications

In vitro and in silico approach towards antimicrobial and antioxidant behaviour of water-soluble chitosan dialdehyde biopolymers

Chitosan dialdehyde (ChDA) was prepared from a three-step process initiated by thermal organic acid hydrolysis, periodate oxidization, and precipitation from native chitosan (NCh). The developed ChDA resulted in an aldehydic content of about 82 % with increased solubility (89 %) and maximum yield (97 %). The functional alteration of the aldehydic (-CHO) group in ChDA was established using vibrational stretching at 1744 cm-1. The increase in the zone of inhibition of ChDA compared to NCh has confirmed the inherent antimicrobial effect against bacterial and fungal species. ChDA showed better antioxidant activity of about 97.4 % (DPPH) and 31.1 % (ABTS) compared to NCh, measuring 45.3 % (DPPH) and 15.9 % (ABTS), respectively. The novel insilico predictions of the ChDA's biocidal activity were confirmed through molecular docking studies. The amino acid moiety such as ARG 110 (A), ASN 206 (A), SER 208 (A), THR 117 (B), ASN 118 (B), and LYS 198 (B) residues of 7B53 peptide from E. coli represents the binding pockets responsible for interaction with aldehyde group of ChDA. Whereas PHE 115 (E), ALA 127 (H), TYR 119 (C), GLN 125 (H), ASN 175 (E), ARG 116 (E), LYS 101 (H), and LYS 129 (H) of 1IYL A peptide from Candida albicans makes possible for binding with ChDA. Hence, the synergistic effect of ChDA as a biocidal compound is found to be plausible in the drug delivery system for therapeutic applications.

Investigating the potential of highly porous zopiclone-loaded 3D electrospun nanofibers for brain targeting via the intranasal route

Nanofibers (NFs) have proven to be very attractive tool as drug delivery plateform among the different plethora of nanosystems, owing to their unique features. They exhibit two- and three-dimensional structures some of which mimic structural environment of the body tissues, in addition to being safe, efficacious, and biocompatible drug delivery platform. Thus, this study embarked on fabricating polyvinyl alcohol/chitosan (PVA/CS) electrospun NFs encapsulating zopiclone (ZP) drug for intranasal brain targeted drug delivery. Electrospun NFs were optimized by adopting a three factor-two level full factorial design. The independent variables were: PVA/CS ratio (X1), flow rate (X2), and applied voltage (X3). The measured responses were: fiber diameter (Y1,nm), pore size (Y2,nm) and ultimate tensile strength (UTS,Y3,MPa). The selected optimum formula had resulted in NFs diameter of 215.90 ± 15.46 nm, pore size 7.12 ± 0.27 nm, and tensile strength around 6.64 ± 0.95 MPa. In-vitro biodegradability testing confirmed proper degradation of the NFs within 8 h. Moreover, swellability and breathability assessment revealed good hydrophilicity and permeability of the prepared NFs. Ex-vivo permeability study declared boosted ex-vivo permeation with an enhancement factor of 2.73 compared to ZP suspension. In addition, optimized NFs formula significantly reduced sleep latency and prolonged sleep duration in rats compared to IV ZP drug solution. These findings demonstrate the feasibility of employing the designed NFs as an effective safe platform for intranasal delivery of ZP for insomnia management.

Nanophycology, the merging of nanoscience into algal research: A review

Nanophycology is recognized as one of the most important and widely used interdisciplinary sciences by creating a connection between nanotechnology on the one hand and phycology on the other hand. Algal nanoparticle biosynthesis is a starting point in studies and research related to nanophycology. Nanophycology consists of two parts, nano and phycology, and by taking advantage of the high potential of algae such as high biological safety, easy production, fast growth, and high stability in the phycology part of this science, which is also known as algology, algae nanoparticles synthesis and make this section related to nanotechnology. In this way, algae are known as factories of biological nanomaterials and cause the production of bio-stable nanotechnology and the removal of environmental pollutants released due to nanochemistry. Nanotechnology produced by algae in the science of nanophycology, due to algae's unique physical and chemical properties compared to other biological entities such as plants, fungi, and bacteria, is used in various fields including medicine, biorefining, purification Water, etc. In this review article, the most important goals of the science of nanophycology, including the biosynthesis of algal nanoparticles and the potential of these compounds in various fields of application, have been examined and discussed.

Thermosensitive composite based on agarose and chitosan saturated with carbon dioxide. Preliminary study of requirements for production of new CSAG bioink

This study introduces a method for producing printable, thermosensitive bioink formulated from agarose (AG) and carbon dioxide-saturated chitosan (CS) hydrogels. The research identified medium molecular weight chitosan as optimal for bioink production, with a preferred chitosan hydrogel content of 40-60 %. Rheological analysis reveals the bioink's pseudoplastic behavior and a sol-gel phase transition between 27.0 and 31.5 °C. The MMW chitosan-based bioink showed also the most stable extrusion characteristic. The choice of chitosan for the production of bioink was also based on the assessment of the antimicrobial activity of the polymer as a function of its molecular weight and the degree of deacetylation, noting significant cell reduction rates for E. coli and S. aureus of 1.72 and 0.54 for optimal bioink composition, respectively. Cytotoxicity assessments via MTT and LDH tests confirm the bioink's safety for L929, HaCaT, and 46BR.1 N cell lines. Additionally, XTT proliferation assay proved the stimulating effect of the bioink on the proliferation of 46BR.1 N fibroblasts, comparable to that observed with Fetal Bovine Serum (FBS). FTIR spectroscopy confirms the bioink as a physical polymer blend. In conclusion, the CS/AG bioink demonstrates the promising potential for advanced spatial cell cultures in tissue engineering applications including skin regeneration.

Trends in sustainable chitosan-based hydrogel technology for circular biomedical engineering: A review

Eco-friendly materials have emerged in biomedical engineering, driving major advances in chitosan-based hydrogels. These hydrogels offer a promising green alternative to conventional polymers due to their non-toxicity, biodegradability, biocompatibility, environmental friendliness, affordability, and easy accessibility. Known for their remarkable properties such as drug encapsulation, delivery capabilities, biosensing, functional scaffolding, and antimicrobial behavior, chitosan hydrogels are at the forefront of biomedical research. This paper explores the fabrication and modification methods of chitosan hydrogels for diverse applications, highlighting their role in advancing climate-neutral healthcare technologies. It reviews significant scientific advancements and trends chitosan hydrogels focusing on cancer diagnosis, drug delivery, and wound care. Additionally, it addresses current challenges and green synthesis practices that support a circular economy, enhancing biomedical sustainability. By providing an in-depth analysis of the latest evidence on climate-neutral management, this review aims to facilitate informed decision-making and foster the development of sustainable strategies leveraging chitosan hydrogel technology. The insights from this comprehensive examination are pivotal for steering future research and applications in sustainable biomedical solutions.

Chitosan microflower-embedded gelatin sponges for advanced wound management and hemostatic applications

The study explored the antimicrobial, antibiofilm, and hemostatic properties of chitosan microflowers (CMF) in sponge form. The main objective was to enhance the preparation of CMF by employing varying quantities of calcium chloride (CaCl2) and tripolyphosphate (TPP). CMF was then combined with gelatin (GE) in different proportions to produce three sponge samples: CMF0@GE, CMF1@GE, and CMF2@GE. The CMF had a morphology like that of a flower and produced surfaces with a porous sponge-like structure. The antibacterial activity, as determined by the zone of inhibition (ZOI), increased with greater doses of CMF. Among the tested samples, CMF2@GE had the greatest activity against Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus, and Enterococcus faecium. CMF2@GE successfully suppressed biofilm formation, decreased clotting time to an average of 212.67 s, and exhibited excellent biocompatibility by preserving over 90 % viability of human skin fibroblast cells at dosages below 100 μg/mL. The results indicated that gelatin sponges filled with CMF have considerable promise as flexible medical instruments for wound healing and infection control.

Nanocarrier optimization: Encapsulating Hydrastis canadensis in chitosan nanoparticles for enhanced antibacterial and dye degradation performance

This study focuses on the optimization of Hydrastis canadensis-based nanocarriers in environmental and microbial applications like antibacterial and dye degradation. Hydrastis canadensis (H. canadensis) is loaded into the nanocarrier using a gelation method. Characterization involves pH analysis, UV-VIS spectrophotometry, scanning electron microscopy, Fourier-transform infrared spectroscopy, dynamic light scattering, high-performance liquid chromatography, encapsulation efficiency. Further antimicrobial activity against Staphylococcus aureus and Escherichia coli were tested. Dye degradation was evaluated at concentrations of 1 % of high molecular (HM) and 1.5 % of low molecular (LM) chitosan nanoparticles with both 3C and 1000C concentrations of the drug. The obtained results confirm the presence of chitosan nanocarrier alongside the pure drug in 1 % HM and 1.5 % LM chitosan particles with a notable encapsulation efficiency activity in both 3C and 1000C concentrations. Antimicrobial studies were carried out using the agar well diffusion method and revealed a significant zone of inhibition of 20 mm and 25 mm for E. coli and S. aureus, respectively in chitosan nanocarrier-loaded samples compared to pure drug and chitosan nanocarriers samples. The dye degradation studies of four dyes methylene blue, methylene orange, methylene red, and safranin using both pure drugs and chitosan nanocarrier-loaded drugs showed the highest percentage of degradation (76 %) against methylene blue in the chitosan nanocarrier-drug loaded formulation. These findings cumulatively underscore chitosan nanoparticles can be used as an effective carrier for Hydrastis Canadensis, with enhanced antimicrobial and dye degradation capabilities. Varied concentrations and molecular weights highlight the versatility of the ionotropic gelation method in optimizing drug delivery. Enhanced efficacy of the nanocarrier was evident in the observed zone of inhibition in antimicrobial testing. The substantial degradation percentage in methylene blue emphasizes the formulation's applicability in environmental dye removal processes, with potential avenues for improvement explored through interactions between the chitosan nanocarrier and H. canadensis characteristics. Future investigations may focus on scaling up the optimized formulation for large-scale applications and exploring release kinetics and comprehensive toxicity assessments for a holistic understanding of potential environmental and biomedical implications.

Effect of a Thermosensitive Hydroxybutyl Chitosan Hydrogel on Postoperative Sequalae and Quality of Life After Impacted Mandibular Third Molar Extraction

BACKGROUND

Third molar (M3) extraction is a common surgery in oral and maxillofacial surgery, and composite wound dressings such as hydroxybutyl chitosan (HBC) may improve postoperative sequala following M3 removal.

PURPOSE

The study purpose was to measure and compare differences in pain, swelling, trismus, wound healing, and quality of life (QOL) between the HBC and the control sides in patients undergoing M3 removal.

STUDY DESIGN, SETTING, SAMPLE

This study is a double-blind, split-mouth, randomized clinical trial. Patients who required M3 removal between June 2022 and May 2023 were included. Exclusion criteria included seafood allergies, smoking, poor oral hygiene, and systemic diseases.

PREDICTOR VARIABLE

The predictor variable was the socket treatment technique. Subjects were randomly assigned to the HBC or control (physiological saline) side.

MAIN OUTCOME VARIABLE

The primary outcome variables, including pain assessed by visual analog scale, swelling, and maximal incisional opening, were measured on the first, third, and seventh postoperative days. The secondary outcome variables included QOL and wound healing score measured on the third and seventh days after surgery.

COVARIATES

The covariates included age, sex, and operation time.

ANALYSES

The Shapiro‒Wilk test was used to evaluate the normality of the data distribution. The paired t test or Wilcoxon signed-rank test was adopted. Statistical significance was set at P < .05.

RESULTS

The study included 60 patients (mean age: 25.81 ± 4.91; 23 (38%) males, 37 (62%) females). A statistically significant difference in the level of pain (HBC: 37.58 ± 4.39 mm, control: 47.00 ± 4.33 mm, day 1, P < .001; 21.88 ± 3.25 mm, 35.95 ± 1.57 mm, day 3, P < .001), maximal incisional opening (23.92 ± 1.38 mm, 18.22 ± 1.82 mm, day 1, P < .001; 30.00 ± 1.61 mm, 23.78 ± 1.70 mm, day 3, P < .001), and swelling (6.86 ± 0.70 mm, 7.15 ± 0.80 mm, day 3, P = .006) was detected after surgery. A statistically significant difference in QOL was detected (HBC: 13.70 ± 1.65, control: 18.60 ± 2.14, day 3, P < .001).

CONCLUSION AND RELEVANCE

The application of HBC hydrogels to wounds after impacted mandibular M3 extraction reduces postoperative sequalae, promotes wound healing and improves postoperative QOL.

Innovative Biomaterials for Bone Tumor Treatment and Regeneration: Tackling Postoperative Challenges and Charting the Path Forward

Surgical resection of bone tumors is the primary approach employed in the treatment of bone cancer. Simultaneously, perioperative interventions, particularly postoperative adjuvant anticancer strategies, play a crucial role in achieving satisfactory therapeutic outcomes. However, the occurrence of postoperative bone tumor recurrence, metastasis, extensive bone defects, and infection are significant risks that can result in unfavorable prognoses or even treatment failure. In recent years, there has been significant progress in the development of biomaterials, leading to the emergence of new treatment options for bone tumor therapy and bone regeneration. This progress report aims to comprehensively analyze the strategic development of unique therapeutic biomaterials with inherent healing properties and bioactive capabilities for bone tissue regeneration. These composite biomaterials, classified into metallic, inorganic non-metallic, and organic types, are thoroughly investigated for their responses to external stimuli such as light or magnetic fields, internal interventions including chemotherapy or catalytic therapy, and combination therapy, as well as their role in bone regeneration. Additionally, an overview of self-healing materials for osteogenesis is provided and their potential applications in combating osteosarcoma and promoting bone formation are explored. Furthermore, the safety concerns of integrated materials and current limitations are addressed, while also discussing the challenges and future prospects.

Development and characterization of Polycaprolactone/chitosan-based scaffolds for tissue engineering of various organs: A review

Research in creating 3D structures mirroring the extracellular matrix (ECM) with accurate environmental cues holds paramount significance in biological applications.Biomaterials that replicate ECM properties-mechanical, physicochemical, and biological-emerge as pivotal tools in mimicking ECM behavior.Incorporating synthetic and natural biomaterials is widely used to produce scaffolds suitable for the intended organs.Polycaprolactone (PCL), a synthetic biomaterial, boasts commendable mechanical properties, albeit with relatively modest biological attributes due to its hydrophobic nature.Chitosan (CTS) exhibits strong biological traits but lacks mechanical resilience for complex tissue regeneration.Notably, both PCL and CTS have demonstrated their application in tissue engineering for diverse types of tissues.Their combination across varying PCL:CTS ratios has increased the likelihood of fabricating scaffolds to address defects in sturdy and pliable tissues.This comprehensive analysis aspires to accentuate their distinct attributes within tissue engineering across different organs.The central focus resides in the role of PCL:CTS-based scaffolds, elucidating their contribution to the evolution of advanced functional 3D frameworks tailored for tissue engineering across diverse organs.Moreover, this discourse delves into the considerations pertinent to each organ.

Chitosan derivatives act as a bio-stimulants in plants: A review

Chitosan has been considered an eco-friendly biopolymer. Chitosan is a natural polycationic linear polysaccharide composed of D-glucosamine and N-acetyl-D-glucosamine linked by β-1,4-glycosidic bonds. Chitosan has been used as an eco-friendly biopolymer for so many agricultural applications. Unfortunately, the relatively poor solubility and poor antimicrobial properties limit its widespread applications in agriculture sciences. Hence, chitosan derivatives are produced via various chemical approaches such as cross-linking, carboxylation, ionic binding, and so on. As an alternative to chemical fertilizers, chitosan derivatives, chitosan conjugates, nanostructures, semisynthetic derivatives, oligo mixes, chitosan nanoparticles, and chitosan nano-carriers are synthesized for various agricultural applications. Its several chemical and physical properties such as biocompatibility, biodegradability, permeability, cost-effectiveness, low toxicity, and environmental friendliness make it useful for many agricultural applications. Hence, popularizing its use as an elicitor molecule for different host-pathogen interaction studies. Thus, the versatile and plethora of chitosan derivatives are gaining momentum in agricultural sciences. Bio-stimulant properties and multifunctional benefits are associated with further prospective research. Therefore, in the present review, we decipher the potential pros and cons of chitosan derivatives in plants.

A comprehensive review on recent progress in chitosan composite gels for biomedical uses

Chitosan (CS) composite gels have emerged as promising materials with diverse applications in biomedicine. This review provides a concise overview of recent advancements and key aspects in the development of CS composite gels. The unique properties of CS, such as biocompatibility, biodegradability, and antimicrobial activity, make it an attractive candidate for gel-based composites. Incorporating various additives, such as nanoparticles, polymers, and bioactive compounds, enhances the mechanical, thermal, and biological and other functional properties of CS gels. This review discusses the fabrication methods employed for CS composite gels, including blending and crosslinking, highlighting their influence on the final properties of the gels. Furthermore, the uses of CS composite gels in tissue engineering, wound healing, drug delivery, and 3D printing highlight their potential to overcome a number of the present issues with drug delivery. The biocompatibility, antimicrobial properties, electroactive, thermosensitive and pH responsive behavior and controlled release capabilities of these gels make them particularly suitable for biomedical applications. In conclusion, CS composite gels represent a versatile class of materials with significant potential for a wide range of applications. Further research and development efforts are necessary to optimize their properties and expand their utility in pharmaceutical and biomedical fields.

Multifunctional chitosan-cross linked- curcumin-tannic acid biocomposites disrupt quorum sensing and biofilm formation in pathogenic bacteria

Natural products have a long history of success in treating bacterial infections, making them a promising source for novel antibacterial medications. Curcumin, an essential component of turmeric, has shown potential in treating bacterial infections and in this study, we covalently immobilized curcumin (Cur) onto chitosan (CS) using glutaraldehyde and tannic acid (TA), resulting in the fabrication of novel biocomposites with varying CS/Cur/TA ratios. Comprehensive characterization of these ternary biocomposites was conducted using FTIR, SEM, XPS, and XRD to assess their morphology, functional groups, and chemical structures. The inhibitory efficacy of these novel biocomposites (n = 4) against the growth and viability of Pseudomonas aeruginosa (ATCC27853) and Chromobacterium violaceum (ATCC12472) was evaluated and the most promising composite (C3) was investigated for its impact on quorum sensing (QS) and biofilm formation in these bacteria. Remarkably, this biocomposite significantly disrupted QS circuits and effectively curtailed biofilm formation in the tested pathogens without inducing appreciable toxicity. These findings underscore its potential for future in vivo studies, positioning it as a promising candidate for the development of biofilm disrupting antibacterial agents.

Herb Extracellular Vesicle-Chitosan-PEGylated Graphene Oxide Conjugate Delivers Estrogen Receptor α Targeting siRNA to Breast Cancer Cells

Herb-based extracellular vesicles (EV), inherently replete with bioactive proteins, RNA, lipids, and other medicinal compounds, are noncytotoxic and uniquely capable of cellular delivery to meet the ever-stringent challenges of ongoing clinical applications. EVs are abundant in nature, affordable, and scalable, but they are also incredibly fragile and stuffed with many biomolecules. To address the low drug binding abilities and poor stability of EVs, we demonstrated herb-based EVs (isolated from neem, mint, and curry leaves) conjugated with chitosan (CS) and PEGylated graphene oxide (GP) that led to their transformation into robust and efficient vectors. The designed conjugates successfully delivered estrogen receptor α (ERα1)-targeting siRNA to breast cancer MCF7 cells. Our data revealed that neem-based EV-CS-GP conjugates were most efficient in cellular siRNA delivery, which could be attributed to hyaluronic acid-mediated recognition of neem EVs by MCF7 cells via CD44 receptors. Our approach shows a futuristic direction in designing clinically viable, sustainable, nontoxic EV-based vehicles that can deliver a variety of functional siRNA cargos.

Investigation of Filtration and Shale Inhibition Characteristics of Chitosan-N-(2-hydroxyl)-propyl trimethylammonium Chloride as Drilling Fluid Additives

Hydrated shale formations often lead to severe drilling problems and may lead to wellbore instability. These instabilities can result in issues such as bit balling, borehole collapse, formation damage, stuck pipe, and low drilling rates. Keeping these fundamental issues with drilling in shale formation in mind, this study is aimed at designing a water-based drilling fluid system for effective shale inhibition, ensuring enhanced wellbore stability and drilling efficiency. The designed mud system comprises a typical base fluid along with newly synthesized chitosan derivative chitosan-N-(2-hydroxyl)-propyl trimethylammonium chloride (HACC) as an additive. This additive was found to be soluble in water and conducive for shale inhibition. The derived product was characterized by field emission scanning electron microscopy, thermogravimetric analysis, and Fourier-transform infrared spectroscopy (FTIR). Various drilling fluid tests, including filtration and rheological experiments, were conducted to evaluate its proficiency as a drilling mud additive. The results showed improvement in rheological and filtration properties after hot rolling at 100 °C in comparison to a conventional shale inhibitor, polyethylenimine. As we increase the concentration of synthesized chitosan derivative from 0.3 to 1.5 w/v%, the filtration loss is reduced from 40% to 65% as compared to the base fluids. Shale recovery tests were also conducted using shale samples from an Indian field to assess its viability for field application. The addition of 0.3 to 1.5 w/v% chitosan derivative resulted in high shale recovery above 88% to 96% at 100 °C compared to polyethylenimine, which showed a change in recovery from 62% to 73%. HACC intercalates into clay platelets, reducing the interlayer spacing between particles and preventing clay from hydrating and swelling. This mechanism of inhibition is evaluated by X-ray diffraction, FTIR, and zeta potential analysis. This bolsters the hypothesis of using the synthesized chitosan derivative as a shale inhibitor.

Advances in Hydrogels for Periodontitis Treatment

Periodontitis is a common condition characterized by a bacterial infection and the disruption of the body's immune-inflammatory response, which causes damage to the teeth and supporting tissues and eventually results in tooth loss. Current therapy involves the systemic and local administration of antibiotics. However, the existing treatments cannot exert effective, sustained release and maintain an effective therapeutic concentration of the drug at the lesion site. Hydrogels are used to treat periodontitis due to their low cytotoxicity, exceptional water retention capability, and controlled drug release profile. Hydrogels can imitate the extracellular matrix of periodontal cells while offering suitable sites to load antibiotics. This article reviews the utilization of hydrogels for periodontitis therapy based on the pathogenesis and clinical manifestations of the disease. Additionally, the latest therapeutic strategies for smart hydrogels and the main techniques for hydrogel preparation have been discussed. The information will aid in designing and preparing future hydrogels for periodontitis treatment.

Effect of Chitosan Irrigant and Lubricating Gel on Bond Strength of Resin Sealer to Radicular Dentin: An In Vitro Study

BACKGROUND

The adhesive strength of sealers to dentin is influenced by various factors, and the presence of a smear layer is among the critical variables. Chitosan, known for its dentin compatibility, has previously demonstrated a reduction in dentin change and resin sealer bond strength comparable to ethylenediaminetetraacetic acid (EDTA) when used as an irrigant and final rinse. The study investigates the impact of chitosan, used as both a lubricating gel and final rinse, on the push-out bond strength of resin sealer.

MATERIALS AND METHOD

Forty single-rooted premolar teeth, each with a fully formed root and a single root canal, were collected post-extraction. During canal preparation, 1 ml sodium hypochlorite (3%) was used for irrigation at every change of instrument, followed by applying specific chelating gel and final rinse for each experimental group. The groups included: Group 1 (17% EDTA chelating gel, final rinse with saline), Group 2 (17% EDTA chelating gel, final rinse with 17% EDTA solution), Group 3 (chitosan chelating gel, final rinse with saline solution), and Group 4 (chitosan chelating gel, final rinse with 0.2% chitosan solution), 10 specimens in each group. After obturation, specimens were sealed and incubated for a week at 37°C with 100% humidity. The universal testing machine was used for push-out tests, and specimens were examined using a scanning electron microscope (SEM) to identify various types of bond failure.

RESULTS

Among the four groups, Group 2 exhibited the highest mean push-out bond strength (7.33 ± 0.26 MPa), followed by Group 4 (5.33 ± 0.25 MPa), Group 1 (4.61 ± 0.30 MPa), and Group 3 (2.94 ± 0.32 MPa). The variations in bond strength suggest a notable impact of the chelating agents and final rinse solutions on the resin sealer's interaction with dentin.

CONCLUSION

The study concludes that the use of EDTA as both a lubricating gel and a final rinse significantly enhances push-out bond strength, outperforming chitosan in this study. Groups with saline as the final rinse (Group 1 and Group 3) exhibited the least bond strength, highlighting the importance of the final rinse in root canal therapy.

The Role of Nanomedicine in Benign Gynecologic Disorders

Nanomedicine has revolutionized drug delivery in the last two decades. Nanoparticles appear to be a promising drug delivery platform in the treatment of various gynecological disorders including uterine leiomyoma, endometriosis, polycystic ovarian syndrome (PCOS), and menopause. Nanoparticles are tiny (mean size < 1000 nm), biodegradable, biocompatible, non-toxic, safe, and relatively inexpensive materials commonly used in imaging and the drug delivery of various therapeutics, such as chemotherapeutics, small molecule inhibitors, immune mediators, protein peptides and non-coding RNA. We performed a literature review of published studies to examine the role of nanoparticles in treating uterine leiomyoma, endometriosis, PCOS, and menopause. In uterine leiomyoma, nanoparticles containing 2-methoxyestradiole and simvastatin, promising uterine fibroid treatments, have been effective in significantly inhibiting tumor growth compared to controls in in vivo mouse models with patient-derived leiomyoma xenografts. Nanoparticles have also shown efficacy in delivering magnetic hyperthermia to ablate endometriotic tissue. Moreover, nanoparticles can be used to deliver hormones and have shown efficacy as a mechanism for transdermal hormone replacement therapy in individuals with menopause. In this review, we aim to summarize research findings and report the efficacy of nanoparticles and nanotherapeutics in the treatment of various benign gynecologic conditions.

Design and In Vitro Activity of Furcellaran/Chitosan Multilayer Microcapsules for the Delivery of Glutathione and Empty Model Multilayer Microcapsules Based on Polysaccharides

In this study, multilayer microcapsules (two-layer and four-layer) based on furcellaran (FUR) and chitosan (CHIT) were produced, enclosing a tripeptide with an antioxidant effect-glutathione-in different concentrations. In addition, for the first time, an empty, four-layer microcapsule based on CHIT and FUR (ECAPS) was obtained, which can be used to contain sensitive, active substances of a hydrophobic nature. Layering was monitored using zeta potential, and the presence of the resulting capsules was confirmed by SEM imaging. In the current study, we also investigated whether the studied capsules had any effect on the Hep G2 cancer cell line. An attempt was also made to identify the possible molecular mechanism(s) by which the examined capsules suppressed the growth of Hep G2 cells. In this report, we demonstrate that the capsules suppressed the growth of cancer cells. This mechanism was linked to the modulation of the AKT/PI3K signaling pathway and the induction of the G2/M arrest cell cycle. Furthermore, the results indicate that the tested multilayer microcapsules induced cell death through an apoptotic pathway.

Glycol Chitosan-Poly(lactic acid) Conjugate Nanoparticles Encapsulating Ciprofloxacin: A Mucoadhesive, Antiquorum-Sensing, and Biofilm-Disrupting Treatment Modality for Bacterial Keratitis

Bacterial keratitis (BK) causes visual morbidity/blindness if not treated effectively. Here, ciprofloxacin (CIP)-loaded nanoparticles (NPs) using glycol chitosan (GC) and poly(lactic acid) (PLA) conjugate at three different ratios (CIP@GC(PLA) NPs (1:1,5,15)) were fabricated. CIP@GC(PLA) NPs (1:1) were more effective than other tested ratios, indicating the importance of optimal hydrophobic/hydrophilic balance for corneal penetration and preventing bacterial invasion. The CIP@GC(PLA) (NPs) (1:1) realized the highest association with human corneal epithelial cells, which were nonirritant to the hen's egg-chorioallantoic membrane test (HET-CAM test) and demonstrated significant antibacterial response in the in vitro minimum inhibitory, bactericidal, live-dead cells, zone of inhibition, and biofilm inhibition assays against the keratitis-inducing pathogen Pseudomonas aeruginosa. The antiquorum sensing activity of GC has been explored for the first time. The NPs disrupted the bacterial quorum sensing by inhibiting the production of virulence factors, including acyl homoserine lactones, pyocyanin, and motility, and caused significant downregulation of quorum sensing associated genes. In the in vivo studies, CIP@GC(PLA) NPs (1:1) displayed ocular retention in vivo (∼6 h) and decreased the opacity and the bacterial load effectively. Overall, the CIP@GC(PLA) NP (1:1) is a biofilm-disrupting antiquorum sensing treatment regimen with clinical translation potential in BK.

Advancements in Photothermal Therapy Using Near-Infrared Light for Bone Tumors

Bone tumors, particularly osteosarcoma, are prevalent among children and adolescents. This ailment has emerged as the second most frequent cause of cancer-related mortality in adolescents. Conventional treatment methods comprise extensive surgical resection, radiotherapy, and chemotherapy. Consequently, the management of bone tumors and bone regeneration poses significant clinical challenges. Photothermal tumor therapy has attracted considerable attention owing to its minimal invasiveness and high selectivity. However, key challenges have limited its widespread clinical use. Enhancing the tumor specificity of photosensitizers through targeting or localized activation holds potential for better outcomes with fewer adverse effects. Combinations with chemotherapies or immunotherapies also present avenues for improvement. In this review, we provide an overview of the most recent strategies aimed at overcoming the limitations of photothermal therapy (PTT), along with current research directions in the context of bone tumors, including (1) target strategies, (2) photothermal therapy combined with multiple therapies (immunotherapies, chemotherapies, and chemodynamic therapies, magnetic, and photodynamic therapies), and (3) bifunctional scaffolds for photothermal therapy and bone regeneration. We delve into the pros and cons of these combination methods and explore current research focal points. Lastly, we address the challenges and prospects of photothermal combination therapy.

Magnetic nanocomposite based on chitosan-gelatin hydrogel embedded with copper oxide nanoparticles: A novel and promising catalyst for the synthesis of polyhydroquinoline derivatives

Nanocatalysts are vital in several domains, such as chemical processes, energy generation, energy preservation, and environmental pollution mitigation. An experimental study was conducted at room temperature to evaluate the catalytic activity of the new gelatin-chitosan hydrogel/CuO/Fe3O4 nanocomposite in the asymmetric Hantzsch reaction. All components of the nanocomposite exhibit a synergistic effect as a Lewis acid, promote the reaction. Dimedone, ammonium acetate, ethyl acetoacetate, and other substituted aldehydes were used to synthesize diverse polyhydroquinoline derivatives. The nanocomposite exhibited exceptional efficacy (over 90 %) and durability (retaining 80 % of its original capacity after 5 cycles) as a catalyst in the one-pot asymmetric synthesis of polyhydroquinoline derivatives. Also, turnover numbers (TON) and turnover frequency (TOF) have been checked for catalyst (TON and TOF = 50,261 and 100,524 h-1) and products. The experiment demonstrated several benefits, such as exceptional product efficacy, rapid reaction time, functioning at ambient temperature without specific requirements, and effortless separation by the use of an external magnet after the reaction is finished. The results suggest the development of a magnetic nanocatalyst with exceptional performance. The composition of the Ge-CS hydrogel/CuO/Fe3O4 nanocomposite was thoroughly analyzed using several methods including FT-IR, XRD, FE-SEM, EDX, VSM, BET, and TGA. These analyses yielded useful information into the composition and characteristics of the nanocomposite, hence further enhancing the knowledge of its possible uses.

Antimicrobial fibres derived from aryl-diazonium conjugation of chitosan with Harakeke (Phormium tenax) and Hemp (Cannabis sativa) Hurd

Surface functionalisation of natural materials to develop sustainable and environmentally friendly antimicrobial fibres has received great research interest in recent years. Herein, chitosan covalent conjugation via aryl-diazonium based chemistry onto Phormium tenax fibres (PTF) and hemp hurds (HH) was investigated. PTF are fibres derived from Harakeke/New Zealand flax, an indigenous and abundant plant source of leaf fibres, which served as an important 19th century export commodity of New Zealand. HH are obtained as a by-product from the hemp (Cannabis sativa) industry and find applications as traditional construction material, animal bedding, chemical absorbent, insulation, fireboard etc. This study reports aryl-diazonium covalent attachment of chitosan and PD13 (6-O-(3-(2-(N,N-dimethylamino)ethylamino)-2-hydroxypropyl)chitosan), a chitosan derivative with improved antibacterial activity, on to PTF and HH. The modification was confirmed using FTIR, XPS, SEM and water contact angle studies. Comparison of aryl-diazonium versus the use of succinic anhydride bridging for chitosan attachment was also investigated, with the diazonium method giving improved results. The treated PTF and HH fibres had good antibacterial activity against Staphylococcus aureus and this study contributes to the development of sustainable antibacterial fibres using bio-based materials.

Injecting hope: chitosan hydrogels as bone regeneration innovators

Spontaneous bone regeneration encounters substantial restrictions in cases of bone defects, demanding external intervention to improve the repair and regeneration procedure. The field of bone tissue engineering (BTE), which embraces a range of disciplines, offers compelling replacements for conventional strategies like autografts, allografts, and xenografts. Among the diverse scaffolding materials utilized in BTE applications, hydrogels have demonstrated great promise as templates for the regeneration of bone owing to their resemblance to the innate extracellular matrix. In spite of the advancement of several biomaterials, chitosan (CS), a natural biopolymer, has garnered significant attention in recent years as a beneficial graft material for producing injectable hydrogels. Injectable hydrogels based on CS formulations provide numerous advantages, including their capacity to absorb and preserve a significant amount of water, their minimally invasive character, the existence of porous structures, and their capability to adapt accurately to irregular defects. Moreover, combining CS with other naturally derived or synthetic polymers and bioactive materials has displayed its effectiveness as a feasible substitute for traditional grafts. We aim to spotlight the composition, production, and physicochemical characteristics and practical utilization of CS-based injectable hydrogels, explicitly focusing on their potential implementations in bone regeneration. We consider this review a fundamental resource and a source of inspiration for future research attempts to pioneer the next era of tissue-engineering scaffold materials.

Therapeutic applications of carbohydrate-based compounds: a sweet solution for medical advancement

Carbohydrates, one of the most abundant biomolecules found in nature, have been seen traditionally as a dietary component of foods. Recent findings, however, have unveiled their medicinal potential in the form of carbohydrates-derived drugs. Their remarkable structural diversity, high optical purity, bioavailability, low toxicity and the presence of multiple functional groups have positioned them as a valuable scaffold and an exciting frontier in contemporary therapeutics. At present, more than 170 carbohydrates-based therapeutics have been granted approval by varying regulatory agencies such as United States Food and Drug Administration (FDA), Japan Pharmaceuticals and Medical Devices Agency (PMDA), Chinese National Medical Products Administration (NMPA), and the European Medicines Agency (EMA). This article explores an overview of the fascinating potential and impact of carbohydrate-derived compounds as pharmacological agents and drug delivery vehicles.

Evaluation of the Potential of Chitosan Nanoparticles as a Delivery Vehicle for Gentamicin for the Treatment of Osteomyelitis

Chitosan nanoparticle delivery systems have the potential for enhancing bone healing and addressing osteomyelitis. The objective was to deliver antimicrobial agents capable of preventing or treating osteomyelitis. Each formulation was optimized to achieve desired characteristics in terms of size (ranging from 100 to 400 nm), PDI (less than 0.5), zeta potential (typically negative), and in vitro release profiles for gentamicin. Entrapment percentages varied with gentamicin ranging from 10% to 65%. The chitosan nanoparticles exhibited substantial antimicrobial efficacy, particularly against P. aeruginosa and MRSA, with zones of inhibition ranging from 13 to 24 mm and a complete reduction in colony forming units observed between 3 and 24 h. These chitosan nanoparticle formulations loaded with antimicrobials hold promise for addressing orthopedic complications.

Intranasal delivery of mitochondria targeted neuroprotective compounds for traumatic brain injury: screening based on pharmacological and physiological properties

Targeting drugs to the mitochondrial level shows great promise for acute and chronic treatment of traumatic brain injury (TBI) in both military and civilian sectors. Perhaps the greatest obstacle to the successful delivery of drug therapies is the blood brain barrier (BBB). Intracerebroventricular and intraparenchymal routes may provide effective delivery of small and large molecule therapies for preclinical neuroprotection studies. However, clinically these delivery methods are invasive, and risk inadequate exposure to injured brain regions due to the rapid turnover of cerebral spinal fluid. The direct intranasal drug delivery approach to therapeutics holds great promise for the treatment of central nervous system (CNS) disorders, as this route is non-invasive, bypasses the BBB, enhances the bioavailability, facilitates drug dose reduction, and reduces adverse systemic effects. Using the intranasal method in animal models, researchers have successfully reduced stroke damage, reversed Alzheimer's neurodegeneration, reduced anxiety, improved memory, and delivered neurotrophic factors and neural stem cells to the brain. Based on literature spanning the past several decades, this review aims to highlight the advantages of intranasal administration over conventional routes for TBI, and other CNS disorders. More specifically, we have identified and compiled a list of most relevant mitochondria-targeted neuroprotective compounds for intranasal administration based on their mechanisms of action and pharmacological properties. Further, this review also discusses key considerations when selecting and testing future mitochondria-targeted drugs given intranasally for TBI.

Magnetic dendritic mesoporous silica nanoparticles based integrated platform for rapid and efficient analysis of saccharides

BACKGROUND

As an essential compound in living organism, saccharides have attracted enormous attentions from scientists in various fields. Understanding the distribution of saccharides in various samples is of great scientific importance. However, the low signal response and lack of specific recognition technology of saccharides and the complex matrix of samples make the analysis of saccharides a very challenge task. Thus, the development of a simple and straightforward strategy for the analysis of saccharides would represent a great contribution to the field.

RESULTS

In this study, by employing the sulfonyl functionalized magnetic dendritic mesoporous silica nanoparticles as the substrate, we develop an integrated platform for analysis of saccharides. The construction of the platform mainly relied on multi-functional boronic acid, which serves as separation and derivation ligands at the same time. In the general procedure, the boronic acid is first immobilized onto the surface of substrate, then the selective enrichment of saccharides can be realized via boronate affinity separation. Finally, by the rational choice of the solution, we are able to elute the labelled complex (boronic acid-saccharide) from the substrate, which can be direct subjected to HPLC-UV analysis. The reliable precision (<15 %), accuracy (80-100 %), reproducibility (<10 %), improved sensitivity (20x) and limited time-consuming (down to minutes) of the proposed platform are experimentally demonstrated.

SIGNIFICANCE AND NOVELTY

The successful quantification of different saccharides (alditols, glucose) in real samples is achieved. The proposed strategy is not only straightforward and fast, but also avoid the requirement of special equipment. With these attractive features, we believe that this strategy will greatly prompt the analysis of saccharides in various samples (eg. food, pharmaceutics and biosamples).

Chitosan-Based Biomaterial in Wound Healing: A Review

Wound healing is an evolving and intricate technique that is vital to the restoration of tissue integrity and function. Over the past few decades, chitosan a biopolymer derived from chitin, became known as an emerging biomaterial in the field of healing wounds due to its distinctive characteristics including biocompatibility, biodegradability, affinity to biomolecules, and wound-healing activity. This natural polymer exhibits excellent healing capabilities by accelerating the development of new skin cells, reducing inflammation, and preventing infections. Due to its distinct biochemical characteristics and innate antibacterial activity, chitosan has been extensively researched as an antibacterial wound dressing. Chronic wounds, such as diabetic ulcers and liver disease, are a growing medical problem. Chitosan-based biomaterials are a promising solution in the domain of wound care. The article analyzes the depth of chitosan-based biomaterials and their impact on wound healing and also the methods to enhance the advantages of chitosan by incorporating bioactive compounds. This literature review is aimed to improve the understanding and knowledge about biomaterials and their use in wound healing.

Valorization of biological waste from insect-based food industry: Assessment of chitin and chitosan potential

Edible mealworms can be farmed to produce high-quality nutrients and proteins, useful as ingredients in human and animal foods. During this process biological waste is produced. This work explores the usage of the biological waste as source to produce chitin and chitosan with different potential applications. Different waste fractions were processed, and the feasibility of chitin isolation was assessed. Chitosan was derived, and films were fabricated and tested for intended uses. Data indicate that biopolymers with different properties can be obtained from multiple biological waste fractions. All samples show antibacterial activity, while chitosan films derived from molt show interesting properties for packaging purposes. Films also trigger the expression of anti-inflammatory phenotype markers in macrophage cells, which may be useful for tissue engineering implantation purposes. Altogether, biological waste from insect farming can be used to extract chitin and chitosan with different properties, and therefore, suitable for different applications.

Exploring the Ocular Absorption Pathway of Fasudil Hydrochloride towards Developing a Nanoparticulate Formulation with Improved Performance

Rho-kinase (ROCK) inhibitors represent a new category of anti-glaucoma medications. Among them, Fasudil hydrochloride, a selective ROCK inhibitor, has demonstrated promising outcomes in glaucoma treatment. It works by inhibiting the ROCK pathway, which plays a crucial role in regulating the trabecular meshwork and canal of Schlemm's aqueous humor outflow. This study aims to investigate the ocular absorption pathway of Fasudil hydrochloride and, subsequently, develop a nanoparticle-based delivery system for enhanced corneal absorption. Employing the ionic gelation method and statistical experimental design, the factors influencing chitosan nanoparticle (Cs NP) characteristics and performance were explored. Fasudil in vitro release and ex vivo permeation studies were performed, and Cs NP ocular tolerability and cytotoxicity on human lens epithelial cells were evaluated. Permeation studies on excised bovine eyes revealed significantly higher Fasudil permeation through the sclera compared to the cornea (370.0 μg/cm2 vs. 96.8 μg/cm2, respectively). The nanoparticle size (144.0 ± 15.6 nm to 835.9 ± 23.4 nm) and entrapment efficiency range achieved (17.2% to 41.4%) were predominantly influenced by chitosan quantity. Cs NPs showed a substantial improvement in the permeation of Fasudil via the cornea, along with slower release compared to the Fasudil aqueous solution. The results from the Hen's Egg Test Chorioallantoic Membrane (HET-CAM) and Bovine Corneal Opacity and Permeability (BCOP) tests indicated good conjunctival and corneal biocompatibility of the formulated chitosan nanoparticles, respectively. Lens epithelial cells displayed excellent tolerance to low concentrations of these nanoparticles (>94% cell viability). To the best of our knowledge, this is the first report on the ocular absorption pathway of topically applied Fasudil hydrochloride where the cornea has been identified as a potential barrier that could be overcome using Cs NPs.

Simultaneous Optimization of Deacetylation Degree and Molar Mass of Chitosan from Shrimp Waste

Shrimp waste is a valuable source for chitin extraction and consequently for chitosan preparation. In the process of obtaining chitosan, a determining step is the chitin deacetylation. The main characteristic of chitosan is the degree of deacetylation, which must be as high as possible. The molar mass is another important parameter that defines its utilizations, and according to these, high or low molar masses are required. The present study is an attempt to optimize the deacetylation step to obtain chitosan with a high degree of deacetylation and high or low molar mass. The study was carried out based on experimental data obtained in the frame of a central composite design where three working parameters were considered: NaOH concentration, liquid:solid ratio, and process duration. The regression models defined for the degree of deacetylation (DD) and for the mean molar mass (MM) of chitosan powders were used in the formulation of optimization problems. The objectives considered were simultaneous maximum DD and maximum/minimum MM for the final chitosan samples. For these purposes, multiobjective optimization problems were formulated and solved using genetic algorithms implemented in Matlab®. The multiple optimal solutions represented by trade-offs between the two objectives are presented for each case.

Preparation and Modification of Collagen/Sodium Alginate-Based Biomedical Materials and Their Characteristics

(1) Background: Collagen and sodium alginate are commonly used in the field of biomedical materials due to their excellent biocompatibility. This study focuses on the preparation, modification, and characterization of collagen/sodium alginate (C/SA)-based biomedical materials. (2) Methods: The characteristics, including surface chemistry, mechanical properties, hygroscopicity, and porosity, were analyzed. The hemostatic activity in vitro was measured using a blood clotting assay and dynamic blood clotting assay. (3) Results: The results from microstructure and porosity measurement revealed that all of the sponges exhibited a porosity of more than 95 percent. The sponge cross-linked with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide (EDC/NHS) showed better tensile strength and lower elongation at break. The sponges cross-linked with EDC/NHS and oxidized sodium alginate (OSA) exhibited the highest hygroscopicity in comparison with the uncross-linked sponge. (4) Conclusions: Our study demonstrated that the C/SA-based material we prepared exhibited a high level of porosity, enabling efficient absorption of tissue exudate and blood. Additionally, the materials revealed excellent hemocompatibility, making them suitable for use as a hemostatic dressing in the field of biomedical materials.

Zinc-Phthalocyanine Loaded PLGA-PVA-Chitosan Nanosystem for the Enhancement of Antidiabetic Activity

Zinc, one of the most common nutraceutical agents, proved to be effective for diabetes as it regulates the blood glucose level by inhibiting glucagon secretion. However, the hepatotoxicity of zinc creates necrosis, hepatic glycogen depletion, and apoptosis of hepatocytes at the concentration of 10 μg/kg. Phthalocyanine, a blue-colored compound, is an aromatic macrocyclic compound with good antioxidant ability owing to its heterocyclic nitrogen conjugation. The conjugation of zinc with phthalocyanine aimed to reduce the toxicity associated with zinc and enhance the antidiabetic activity at a lower dose. Hence, the present research work possessed the insights of the synthetic aspect of zinc with phthalocyanine along with its entrapment in the poly(lactic-co-glycolic acid) (PLGA)-chitosan nanosystem via oral administration in the treatment of diabetes. A nanoprecipitation technique was implemented for the synthesis of PLGA chitosan nanoparticles, and formulation was further optimized using a central composite design. Twenty trials provided by the software selected optimum concentrations of PLGA, poly(vinyl alcohol) (PVA), and chitosan in consideration with particle size up to 335.6 nm, zeta potential 27.87 mV, and entrapment efficiency of 75.67 ± 8.13%. Addition of chitosan to the nanocarrier system for controlling the release of the drug for 3 days was accompanied by the improvement in the glucose level within 28 days. The delivery of the nanoparticles showed enhancement in the cholesterol, triglyceride, alkaline phosphatase (ALP), urine parameters, and pro-inflammatory cytokines. The application of DoE (design of experiments) for the optimization of the nanoparticles established a controlled release formulation for diabetes, which displayed safety and effectiveness in streptozotocin (STZ)-induced diabetic rats.

A significant antibiofilm and antimicrobial activity of chitosan-polyacrylic acid nanoparticles against pathogenic bacteria

Chitosan is known to exert antimicrobial activity without the need for any chemical modification; however, new derivatives of chitosan can be created to target multi-drug resistant bacteria. In this study, chitosan (CS) was cross-linked with sodium tripolyphosphate to form nanoparticles, which were then coated with polyacrylic acid (PAA). The SEM images revealed that the CS-PAA nanoparticles had spherical shapes with smooth surfaces and the size of the dried nanoparticles was approximately 222 nm. Biofilm formation was significantly inhibited by 0.5 mg/mL of CS-PAA. In-situ optical microscopy showed that CS-PAA nanoparticles inhibited the bacterial biofilm formation in Campylobacter jejuni, Pseudomonas aeruginosa, and Escherichia coli after a single treatment with 40 μg. Additionally, 20 µg of CS-PAA nanoparticles demonstrated antibacterial activity against the growth of C. jejuni, P. aeruginosa, and E. coli with notable inhibitory zones of 9, 12, and 13 mm, respectively (P < 0.01). The development of a novel and ecofriendly method for the preparation of chitosan nanoparticles through an interaction of chitosan with PAA shows promise tool to combat bacterial infections and validates effective antibacterial and antibiofilm properties against antibiotic resistant pathogens.

Chitosan scaffolds: Expanding horizons in biomedical applications

Chitosan, a natural polysaccharide from chitin, shows promise as a biomaterial for various biomedical applications due to its biocompatibility, biodegradability, antibacterial activity, and ease of modification. This review overviews "chitosan scaffolds" use in diverse biomedical applications. It emphasizes chitosan's structural and biological properties and explores fabrication methods like gelation, electrospinning, and 3D printing, which influence scaffold architecture and mechanical properties. The review focuses on chitosan scaffolds in tissue engineering and regenerative medicine, highlighting their role in bone, cartilage, skin, nerve, and vascular tissue regeneration, supporting cell adhesion, proliferation, and differentiation. Investigations into incorporating bioactive compounds, growth factors, and nanoparticles for improved therapeutic effects are discussed. The review also examines chitosan scaffolds in drug delivery systems, leveraging their prolonged release capabilities and ability to encapsulate medicines for targeted and controlled drug delivery. Moreover, it explores chitosan's antibacterial activity and potential for wound healing and infection management in biomedical contexts. Lastly, the review discusses challenges and future objectives, emphasizing the need for improved scaffold design, mechanical qualities, and understanding of interactions with host tissues. In summary, chitosan scaffolds hold significant potential in various biological applications, and this review underscores their promising role in advancing biomedical science.

Fluorescence and Biochemical Assessment of the Chitin and Chitosan Content of Cryptococcus

The cell wall of the fungal pathogens Cryptococcus neoformans and C. gattii is critical for cell wall integrity and signaling external threats to the cell, allowing it to adapt and grow in a variety of changing environments. Chitin is a polysaccharide found in the cell walls of fungi that is considered to be essential for fungal survival. Chitosan is a polysaccharide derived from chitin via deacetylation that is also essential for cryptococcal cell wall integrity, fungal pathogenicity, and virulence. Cryptococcus has evolved mechanisms to regulate the amount of chitin and chitosan during growth under laboratory conditions or during mammalian infection. Therefore, levels of chitin and chitosan have been useful phenotypes to define mutant Cryptococcus strains. As a result, we have developed and/or refined various qualitative and quantitative methods for measuring chitin and chitosan. These techniques include those that use fluorescent probes that are known to bind to chitin (e.g., calcofluor white and wheat germ agglutinin), as well as those that preferentially bind to chitosan (e.g., eosin Y and cibacron brilliant red 3B-A). Techniques that enhance the localization and quantification of chitin and chitosan in the cell wall include (i) fluorescence microscopy, (ii) flow cytometry, (iii) and spectrofluorometry. We have also modified two highly selective biochemical methods to measure cellular chitin and chitosan content: the Morgan-Elson and the 3-methyl-2-benzothiazolone hydrazine hydrochloride (MBTH) assays, respectively.

Research Progress of Chitosan-based Multifunctional Nanoparticles in Cancer Targeted Therapy

Conventional tumor therapeutic modalities, such as radiotherapy, chemotherapy, and surgery, involve low tumor inhibition efficiency, non-targeted drug delivery, and side effects. The development of novel and practical nano-drug delivery systems (DDSs) for targeted tumor therapy has become particularly important. Among various bioactive nanoparticles, chitosan is considered a suitable candidate for drug delivery due to its nontoxicity, good biocompatibility, and biodegradability. The amino and hydroxyl groups of chitosan endow it with the diverse function of chemical modification, thereby improving its physical and biological properties to meet the requirements of advanced biomedical applications. Therefore, it is necessary to review the property and applications of chitosan- based materials in biomedicine. In this review, the characteristics of chitosan related to its applications are first introduced, and then the preparation and modification of chitosan-based nanoparticles, including the function tailoring of chitosan-modified nanoparticles, are demonstrated and discussed. Finally, the opportunities and challenges of chitosan- based nanomaterials in this emerging field are proposed from the perspective of the rational and systematic design for the biomedicine field.

Chitosan-functionalized bioplatforms and hydrogels in breast cancer: immunotherapy, phototherapy and clinical perspectives

Breast cancer is the most common and malignant tumor among women. Chitosan (CS)-based nanoparticles have been introduced into breast cancer therapy as a way to increase the targeted delivery of drugs and genes to the tumor site. CS nanostructures suppress tumorigenesis by enhancing both the targeted delivery of cargo (drug and gene) and its accumulation in tumor cells. The tumor cells internalize CS-based nanoparticles through endocytosis. Moreover, chitosan nanocarriers can also induce phototherapy-mediated tumor ablation. Smart and multifunctional types of CS nanoparticles, including pH-, light- and redox-responsive nanoparticles, can be used to improve the potential for breast cancer removal. In addition, the acceleration of immunotherapy by CS nanoparticles has also been achieved, and there is potential to develop CS-nanoparticle hydrogels that can be used to suppress tumorigenesis.

Sustainable valorization approaches on crustacean wastes for the extraction of chitin, bioactive compounds and their applications - A review

The unscientific disposal of the most abundant crustacean wastes, especially those derived from marine sources, affects both the economy and the environment. Strategic waste collection and management is the need of the hour. Sustainable valorization approaches have played a crucial role in solving those issues as well as generating wealth from waste. The shellfishery wastes are rich in valuable bioactive compounds such as chitin, chitosan, minerals, carotenoids, lipids, and other amino acid derivatives. These value-added components possessed pleiotropic applications in different sectors viz., food, nutraceutical, cosmeceutical, agro-industrial, healthcare, and pharmaceutical sectors. The manuscript covers the recent status, scope of shellfishery management, and different bioactive compounds obtained from crustacean wastes. In addition, both sustainable and conventional routes of valorization approaches were discussed with their merits and demerits along with their combinations. The utilization of nano and microtechnology was also included in the discussion, as they have become prominent research areas in recent years. More importantly, the future perspectives of crustacean waste management and other potential valorization approaches that can be implemented on a large scale.

Prospecting the cancer therapeutic edge of chitosan-based gold nanoparticles through conformation selective binding to the parallel G-quadruplex formed by short telomeric DNA sequence: A multi-spectroscopic approach

The biological relevance of G4 structures formed in telomere & oncogenes promoters make them extremely crucial therapeutic target for cancer treatment. Herein, we have synthesized chitosan-based gold nanoparticles (CH-Au NPs) through green method and have investigated their interaction with G4 structures formed by short telomeric sequences to evaluate their potential for targeting G4 structures. Firstly, we have characterized morphological/physical attributes of synthesized CH-Au NPs and salt dependent structural aspects of model G-rich DNA sequence, 12-mer d(T2G4)2 [TETRA] using spectroscopic and biophysical techniques. The molecular interactions between CH-Au NPs and parallel/antiparallel TETRA G4 structures were evaluated using UV-Visible, CD, Fluorescence, CD melting, DLS and Zeta potential studies. The experimental data indicated that CH-Au NPs showed strong binding interactions with Parallel TETRA G4 and provided thermal stabilization to the structure, whereas their interactions with Antiparallel TETRA G4 DNA and Ct-DNA (DNA duplex) were found to be negligible. Further, CH-Au NPs were also investigated for their selectivity aptitude for different G4 structures formed by human telomeric sequences; d(T2AG3)3 [HUM-12] and d(T2AG3)4T [HUM-25]. Our findings suggested that CH-Au NPs exhibited topology specific binding aptitude towards G4 structure, which can be utilized to inhibit/modulate crucial biological functions for potential anticancer activity.

Folic acid-chitosan functionalized polymeric nanocarriers to treat colon cancer

In the present study, polymeric nanoparticles loaded with IRI and quercetin, a p-gp inhibitor, were developed to target folate receptors expressed by colon cancer cells for oral targeted delivery. This work reports the development of PNPs with an entrapment efficiency of 41.26 ± 0.56 % for IRI and 55.83 ± 4.51 for QT. PNPs were further surface modified using chitosan-folic acid conjugates for better targetability to obtain folic acid-chitosan coated nanoparticles. DLS and FeSEM revealed particles in the nanometric size range with spherical morphology, while FTIR and DSC provided details on their structure and encapsulation. In vitro drug release studies confirmed a sustained release pattern of IRI and QT, while cell line studies confirmed the superiority of C-FA-PNPs when tested on Caco2 cells. Pharmacodynamic studies in colon cancer induced rats showed similar efficacy for PNPs and C-FA-PNPs. Further examination from a bio-distribution study in healthy rats, revealed the failure of C-FA-PNPs to deliver the drugs to the colon adequately, while the PNPs improved the available concentration of IRI at the colon by almost 1.8 folds when compared to the available marketed product. Hence, the developed PNP formulation sticks out as a plausible substitute for the intravenous dosage forms of IRI which have been conventionally prevailing.

Fabrication of gelatin-incorporated nanoporous chitosan-based membranes for potential water desalination applications

Membrane technology has extensively been used in diverse phenomena such as separation, purification and controlled transportation. Herein, gelatin-incorporated porous chitosan membranes have been prepared using the sol-gel approach for potential water desalination applications. The porogens of poly(ethylene glycol) and Triton X-100 were employed for the mentioned purpose. The prepared porous membranes have been characterized for surface chemical, structural, thermal, mechanical and functional attributes using appropriate analytical approaches. Electron microscopy expressed porous surface morphologies of the resultant films with an average pore size of 14.5 nm. The infrared analysis demonstrated a successful crosslinking of the precursors in the resulting membranes via maleic anhydride. Differential scanning calorimetry analysis disclosed acceptable thermal stability of the test membranes, workable above ambient temperatures. The membrane expressed a water contact of 68.59°, which indicated moderate hydrophilicity, thus allowing controlled transport of the aqueous media. The resultant gelatin/chitosan porous membrane exhibited a porosity of 98 % against kerosene oil. In contrast, the flowability of 7.14 (ethanol), 5.00 (distilled water) and 0.53 (ethylene glycol) mL/min has been recorded against the mentioned liquids. The membrane efficiently purified the local canal water to permissible limits. Such membranes have been qualified for potential applications in water purification systems.

Orally-administered nanomedicine systems targeting colon inflammation for the treatment of inflammatory bowel disease: latest advances

Inflammatory bowel disease (IBD) is a chronic and idiopathic condition that results in inflammation of the gastrointestinal tract, leading to conditions such as ulcerative colitis and Crohn's disease. Commonly used treatments for IBD include anti-inflammatory drugs, immunosuppressants, and antibiotics. Fecal microbiota transplantation is also being explored as a potential treatment method; however, these drugs may lead to systemic side effects. Oral administration is preferred for IBD treatment, but accurately locating the inflamed area in the colon is challenging due to multiple physiological barriers. Nanoparticle drug delivery systems possess unique physicochemical properties that enable precise delivery to the target site for IBD treatment, exploiting the increased permeability and retention effect of inflamed intestines. The first part of this review comprehensively introduces the pathophysiological environment of IBD, covering the gastrointestinal pH, various enzymes in the pathway, transport time, intestinal mucus, intestinal epithelium, intestinal immune cells, and intestinal microbiota. The second part focuses on the latest advances in the mechanism and strategies of targeted delivery using oral nanoparticle drug delivery systems for colitis-related fields. Finally, we present challenges and potential directions for future IBD treatment with the assistance of nanotechnology.

Ameliorative Effects of Cumin Extract-Encapsulated Chitosan Nanoparticles on Skeletal Muscle Atrophy and Grip Strength in Streptozotocin-Induced Diabetic Rats

Skeletal muscle atrophy is a disorder characterized by reductions in muscle size and strength. Cumin extract (CE) possesses anti-inflammatory, antioxidant, and hypoglycemic properties. Its pharmaceutical applications are hindered by its low water solubility and by its cytotoxicity when administered at high doses. In this study, we have developed a simplified water distillation method using a rotary evaporator to isolate the active components in cumin seeds. The anti-inflammatory effects of CE and its potential to ameliorate skeletal muscle atrophy in rats with streptozotocin (STZ)-induced diabetes were evaluated. The half-maximal inhibitory concentration (IC50) of CE for cells was 80 μM. By encapsulating CE in chitosan nanoparticles (CECNs), an encapsulation efficacy of 87.1% was achieved with a slow release of 90% of CE after 24 h of culturing, resulting in CECNs with significantly reduced cytotoxicity (IC50, 1.2 mM). Both CE and CECNs significantly reduced the inflammatory response in interleukin (IL)-6 and IL-1β assays. STZ-induced diabetic rats exhibited sustained high blood glucose levels (>16.5 mmol/L), small and damaged pancreatic β islets, and skeletal muscle atrophy. CE and CECN treatments ameliorated skeletal muscle atrophy, recovered muscle fiber striated appearance, increased grip strength, and decreased IL-6 level. Furthermore, CE and CECNs led to a reduction of damage to the pancreas, restoring its morphological phenotype, increasing serum insulin levels, and lowering blood glucose levels in STZ-induced diabetic rats. Taken together, treatment with CECNs over a 6-week period yielded positive ameliorative effects in STZ-induced rats of muscle atrophy.

Enhancing Physicochemical Properties and Biocompatibility of Hollow Porous Iron Oxide Nanoparticles through Polymer-Based Surface Modifications

In this study, we synthesized hollow porous iron oxide nanoparticles (HPIONPs) with surface modifications using polymers, specifically chitosan (Chi), polyethylene glycol (PEG), and alginate (Alg), to improve colloidal stability and biocompatibility. For colloidal stability, Alg-coated HPIONPs maintained size stability up to 24 h, with only an 18% increase, while Chi, PEG, and uncoated HPIONPs showed larger size increases ranging from 64 to 140%. The biocompatibility of polymer-coated HPIONPs was evaluated by assessing their cell viability, genotoxicity, and hemocompatibility. Across tested concentrations from 6.25 to 100 μg/mL, both uncoated and polymer-coated HPIONPs showed minimal cytotoxicity against three normal cell lines: RAW264.7, 3T3-L1, and MCF10A, with cell viability exceeding 80% at the highest concentration. Notably, polymer-coated HPIONPs exhibited nongenotoxicity based on the micronucleus assay and showed hemocompatibility, with only 2-3% hemolysis in mouse blood, in contrast to uncoated HPIONPs which exhibited 4-5%. Furthermore, we evaluated the cytotoxicity of HPIONPs on MDA-MB-231 breast cancer cells after a 2 h exposure to a stationary magnetic field, and the results showed the highest cell death of 38 and 29% when treated with uncoated and polymer-coated HPIONPs at 100 μg/mL, respectively. This phenomenon is attributed to iron catalyzing the Fenton and Haber-Weiss reactions, leading to reactive oxygen species (ROS)-dependent cell death (r ≥ 0.98). In conclusion, the hydrothermal synthesis and subsequent surface modification of HPIONPs with polymers showed improved colloidal stability, nongenotoxicity, and hemocompatibility compared to uncoated HPIONPs while maintaining closely similar levels of cytotoxicity against both normal and cancer cells. This research has paved the way for further exploration of polymer coatings to enhance the overall performance and safety profile of magnetic nanoparticles in delivering anticancer drugs.

Application of Injectable Hydrogels as Delivery Systems in Spinal Cord Injury

Spinal cord injury (SCI) is a severe neurological injury caused by traffic accidents, trauma, or falls, which leads to significant loss of sensory, motor, and autonomous functions and seriously affects the patient's life quality. Although considerable progress has been made in mitigating secondary injury and promoting the regeneration/repair of SCI, the therapeutic effects need to be improved due to drug availability. Given their good biocompatibility, biodegradability, and low immunogenicity, injectable hydrogels can be used as delivery systems to achieve controlled release of drugs and other substances (cells and proteins, etc.), offering new hope for SCI repair. In this article, we summarized the types of injectable hydrogels, analyzed their application as delivery systems in SCI, and further discussed the mechanisms of hydrogels in the treatment of SCI, such as anti-inflammatory, antioxidant, anti-apoptosis, and pro-neurogenesis. Moreover, we highlighted the potential benefits of hydrogels in the treatment of SCI in combination with therapies, including the recent advances and achievements of these promising tools. Our review may offer new strategies for the development of SCI treatments based on injectable hydrogels as delivery systems.

Polysaccharide-Based Nanogels to Overcome Mucus, Skin, Cornea, and Blood-Brain Barriers: A Review

Nanocarriers have been extensively developed in the biomedical field to enhance the treatment of various diseases. However, to effectively deliver therapeutic agents to desired target tissues and enhance their pharmacological activity, these nanocarriers must overcome biological barriers, such as mucus gel, skin, cornea, and blood-brain barriers. Polysaccharides possess qualities such as excellent biocompatibility, biodegradability, unique biological properties, and good accessibility, making them ideal materials for constructing drug delivery carriers. Nanogels, as a novel drug delivery platform, consist of three-dimensional polymer networks at the nanoscale, offering a promising strategy for encapsulating different pharmaceutical agents, prolonging retention time, and enhancing penetration. These attractive properties offer great potential for the utilization of polysaccharide-based nanogels as drug delivery systems to overcome biological barriers. Hence, this review discusses the properties of various barriers and the associated constraints, followed by summarizing the most recent development of polysaccharide-based nanogels in drug delivery to overcome biological barriers. It is expected to provide inspiration and motivation for better design and development of polysaccharide-based drug delivery systems to enhance bioavailability and efficacy while minimizing side effects.

Hydrogels with Reversible Crosslinks for Improved Localised Stem Cell Retention: A Review

Successful stem cell applications could have a significant impact on the medical field, where many lives are at stake. However, the translation of stem cells to the clinic could be improved by overcoming challenges in stem cell transplantation and in vivo retention at the site of tissue damage. This review aims to showcase the most recent insights into developing hydrogels that can deliver, retain, and accommodate stem cells for tissue repair. Hydrogels can be used for tissue engineering, as their flexibility and water content makes them excellent substitutes for the native extracellular matrix. Moreover, the mechanical properties of hydrogels are highly tuneable, and recognition moieties to control cell behaviour and fate can quickly be introduced. This review covers the parameters necessary for the physicochemical design of adaptable hydrogels, the variety of (bio)materials that can be used in such hydrogels, their application in stem cell delivery and some recently developed chemistries for reversible crosslinking. Implementing physical and dynamic covalent chemistry has resulted in adaptable hydrogels that can mimic the dynamic nature of the extracellular matrix.

Agaricus bisporus Extract Exerts an Anti-Obesity Effect in High-Fat Diet-Induced Obese C57BL/6N Mice by Inhibiting Pancreatic Lipase-Mediated Fat Absorption

Agaricus bisporus is well known as a source of polysaccharides that could improve human health. The objective of this study was to explore the anti-obesity effect of A. bisporus extract (ABE), abundant in polysaccharides, and its underlying mechanism. Pancreatic lipase inhibitory activity in vitro was determined after treatment with ABE and chitosan. Treatment with ABE and chitosan significantly decreased pancreatic lipase activity. Five-week-old male SD rats were randomly divided into three groups for acute feeding with vehicle, ABE at 80 mg/kg body weight (BW)/day, and ABE at 160 mg/kg BW/day. ABE dose-dependently increased plasma lipid clearance in an oral lipid tolerance test. Five-week-old male C57BL/6N mice were fed a control diet (CD), a high-fat diet (HFD), an HFD with ABE at 80 mg/kg BW/day, ABE at 160 mg/kg BW/day, or chitosan at 160 mg/kg BW/day for eight weeks. HFD-fed mice showed significant increases in body weight, fat mass, white adipose tissue, average lipid droplet size, and serum levels of glucose, triglyceride, ALT, and AST compared to those in the CD group. However, ABE or chitosan administration ameliorated these increases. ABE or chitosan significantly reduced dietary efficiency and increased fecal excretion levels of lipids, triglycerides, and total cholesterol. These in vitro and in vivo findings suggest that ABE might act as an anti-obesity agent by inhibiting pancreatic lipase-mediated lipid absorption, at least in part.