Preparation, characterization, and potential application of chitosan, chitosan derivatives, and chitosan metal nanoparticles in pharmaceutical drug delivery

SIS membrane modification to improve antimicrobial and osteogenic properties for guide bone regeneration

The guided bone regeneration (GBR) technique is the most common and durable approach to repairing bone defects in periodontal surgery. However, membrane exposure causes bacterial infiltration, which lowers the functional integrity of the barrier membrane and destroys bone repair. Here, an antibacterial peptide-modified small intestinal submucosa (SIS) membrane is used as a new GBR membrane for effective bone regeneration. The peptide JH8194 was placed into chitosan microspheres to preserve its stability and allow for sustained release, which realizes rapid and efficient functional modification of the SIS membrane. Biocompatibility and certain antibacterial activities were found in the modified SIS membrane (SIS@CS-JH8194). Additionally, in vitro experiments showed that SIS@CS-JH8194 promoted the expression of osteogenic-related factors and decreased the secretion of inflammatory factors in rat bone mesenchymal stem cells. In vivo experiments showed that SIS@CS-JH8194 could effectively promote bone regeneration in rat skull defects. In this work, we created a new antibacterial GBR membrane to help avoid postoperative infection and improve bone tissue regeneration.

Advanced applications of sustainable and biological nano-polymers in agricultural production

Though still in its infancy, the use of nanotechnology has shown promise for improving and enhancing agriculture: nanoparticles (NP) offer the potential solution to depleted and dry soils, a method for the controlled release of agrochemicals, and offer an easier means of gene editing in plants. Due to the continued growth of the global population, it is undeniable that our agricultural systems and practices will need to become more efficient in the very near future. However, this new technology comes with significant worry regarding environmental contamination. NP applied to soils could wash into aquifers and contaminate drinking water, or NP applied to food crops may carry into the end product and contaminate our food supply. These are valid concerns that are not likely to be fully answered in the immediate future due to the complexity of soil-NP interactions and other confounding variables. Therefore, it is obviously preferred that NP used outdoors at this early stage be biodegradable, non-toxic, cost-effective, and sustainably manufactured. Fortunately, there are many different biologically derived, cost-efficient, and biocompatible polymers that are suitable for agricultural applications. In this mini-review, we discuss some promising organic nanomaterials and their potential use for the optimization and enhancement of agricultural practices.

The Use of Chitosan Nanoparticles for Delivery of CpG ODN in Treatment of Allergic Balb/C Mice

Background

This study aims to prepare high stability chitosan nanoparticles (CNP) and examine the ability of CNP in CpG-ODN delivery when treating allergic mice model.

Methods

Preparation and characterization of CNP were performed by ionic gelation, dynamic light scattering, and zeta sizer. The CNP cytotoxicity and activation ability of CpG ODN delivered with CNP were tested using a cell counting kit-8 and Quanti blue method. Allergic mice were injected intraperitoneal with 10 ug ovalbumin on day 0 and 7, and then treated with intranasal CpG ODN/CpG ODN, delivered with CNP/CNP, on the third week three times per week for three weeks. The ELISA method measured cytokine and IgE profiles in the allergic mice's plasma and spleen.

Results

CNP results have sizes 27.73 nm±3.67 dan 188.23 nm±53.47, spherical in shape and non-toxic, and did not alter the NF-κB activation of CpG ODN in RAW-blue cells. The application of CpG ODN delivered by chitosan nanoparticles shows no statistical difference between groups of IFN-γ, IL-10, and IL-13 in Balb/c mice's plasma and spleen, in contrast with IgE level.

Conclusions

The results showed that using chitosan nanoparticles as a delivery system for CpG ODN has the potency to safely CpG ODN efficacy.

Sequential gastrodin release PU/n-HA composite scaffolds reprogram macrophages for improved osteogenesis and angiogenesis

Wound healing is a highly orchestrated process involving a variety of cells, including immune cells. Developing immunomodulatory biomaterials for regenerative engineering applications, such as bone regeneration, is an appealing strategy. Herein, inspired by the immunomodulatory effects of gastrodin (a bioactive component in traditional Chinese herbal medicine), a series of new immunomodulatory gastrodin-comprising biodegradable polyurethane (gastrodin-PU) and nano-hydroxyapatite (n-HA) (gastrodin-PU/n-HA) composites were developed. RAW 264.7 macrophages, rat bone marrow mesenchymal stem cells (rBMSCs), and human umbilical vein endothelial cells (HUVECs) were cultured with gastrodin-PU/n-HA containing different concentrations of gastrodin (0.5%, 1%, and 2%) to decipher their immunomodulatory effects on osteogenesis and angiogenesis in vitro. Results demonstrated that, compared with PU/n-HA, gastrodin-PU/n-HA induced macrophage polarization toward the M2 phenotype, as evidenced by the higher expression level of pro-regenerative cytokines (CD206, Arg-1) and the lower expression of pro-inflammatory cytokines (iNOS). The expression levels of osteogenesis-related factors (BMP-2 and ALP) in the rBMSCs and angiogenesis-related factors (VEGF and BFGF) in the HUVECs were significantly up-regulated in gastrodin-PU/n-HA/macrophage-conditioned medium. The immunomodulatory effects of gastrodin-PU/n-HA to reprogram macrophages from a pro-inflammatory (M1) phenotype to an anti-inflammatory and pro-healing (M2) phenotype were validated in a rat subcutaneous implantation model. And the 2% gastrodin-PU/n-HA significantly decreased fibrous capsule formation and enhanced angiogenesis. Additionally, 2% gastrodin-PU/n-HA scaffolds implanted in the rat femoral condyle defect model showed accelerated osteogenesis and angiogenesis. Thus, the novel gastrodin-PU/n-HA scaffold may represent a new and promising immunomodulatory biomaterial for bone repair and regeneration.

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A new immunomodulatory gastrodin-PU/n-HA biomaterial has been developed.

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The gastrodin-PU/n-HA triggered M2 macrophage polarization.

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The osteogenesis and angiogenesis were enhanced in response to the local immune microenvironment.

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The findings prove a therapeutic strategy in bone defect and other inflammatory osteoimmune disorders.

Fabrication of Biodegradable and Biocompatible Functional Polymers for Anti-Infection and Augmenting Wound Repair

The problem of bacteria-induced infections threatens the lives of many patients. Meanwhile, the misuse of antibiotics has led to a significant increase in bacterial resistance. There are two main ways to alleviate the issue: one is to introduce antimicrobial agents to medical devices to get local drug releasing and alleviating systemic toxicity and resistance, and the other is to develop new antimicrobial methods to kill bacteria. New antimicrobial methods include cationic polymers, metal ions, hydrophobic structures to prevent bacterial adhesion, photothermal sterilization, new biocides, etc. Biodegradable biocompatible synthetic polymers have been widely used in the medical field. They are often used in tissue engineering scaffolds as well as wound dressings, where bacterial infections in these medical devices can be serious or even fatal. However, such materials usually do not have inherent antimicrobial properties. They can be used as carriers for drug delivery or compounded with other antimicrobial materials to achieve antimicrobial effects. This review focuses on the antimicrobial behavior, preparation methods, and biocompatibility testing of biodegradable biocompatible synthetic polymers. Degradable biocompatible natural polymers with antimicrobial properties are also briefly described. Finally, the medical applications of these polymeric materials are presented.

Biosynthesis MgO and ZnO nanoparticles using chitosan extracted from Pimelia Payraudi Latreille for antibacterial applications

Chitosan (CS) is one of the most abundant biopolymers in nature with superior properties such as biocompatibility, biodegradability, lack of toxicity, antimicrobial activity, acceleration of wound healing, and stimulation of the immune system. In this study, chitosan was extracted from the exoskeletons of beetles (Pimelia payraudi latreille) and then used for the biosynthesis of highly pure MgO NPs and ZnO NPs by a facile greener route. The extracted chitosan exhibited excellent physicochemical properties, including high extraction yield (39%), high degree of deacetylation (90%), low ash content (1%), high fat-binding capacity (366%), and unusual crystallinity index (51%). The MgO NPs and ZnO NPs exhibited a spherical morphology with crystallite sizes of 17 nm and 29 nm, particle sizes of about 20-70 nm and 30-60 nm, and band gap energies of 4.43 and 3.34 eV, respectively. Antibacterial assays showed that the extracted chitosan exhibited high antibacterial activity against Gram-positive and -negative bacteria, while ZnO NPs showed much stronger antibacterial activity against Gram-positive bacteria than against Gram-negative bacteria. For MgO NPs, the antibacterial activity against Gram-positive bacteria was lower than against Gram-negative bacteria. The results suggest that the synthesized MgO NPs and ZnO NPs are excellent antibacterial agents for therapeutic applications.

Mechanism and Prospect of Gastrodin in Osteoporosis, Bone Regeneration, and Osseointegration

Gastrodin, a traditional Chinese medicine ingredient, is widely used to treat vascular and neurological diseases. However, recently, an increasing number of studies have shown that gastrodin has anti-osteoporosis effects, and its mechanisms of action include its antioxidant effect, anti-inflammatory effect, and anti-apoptotic effect. In addition, gastrodin has many unique advantages in promoting bone healing in tissue engineering, such as inducing high hydrophilicity in the material surface, its anti-inflammatory effect, and pro-vascular regeneration. Therefore, this paper summarized the effects and mechanisms of gastrodin on osteoporosis and bone regeneration in the current research. Here we propose an assumption that the use of gastrodin in the surface loading of oral implants may greatly promote the osseointegration of implants and increase the success rate of implants. In addition, we speculated on the potential mechanisms of gastrodin against osteoporosis, by affecting actin filament polymerization, renin-angiotensin system (RAS) and ferroptosis, and proposed that the potential combination of gastrodin with Mg2+, angiotensin type 2 receptor blockers or artemisinin may greatly inhibit osteoporosis. The purpose of this review is to provide a reference for more in-depth research and application of gastrodin in the treatment of osteoporosis and implant osseointegration in the future.

Preparation of Paclitaxel-Encapsulated Bio-Functionalized Selenium Nanoparticles and Evaluation of Their Efficacy against Cervical Cancer

The potentiality of nanomedicine in the cancer treatment being widely recognized in the recent years. In the present investigation, the synergistic effects of chitosan-modified selenium nanoparticles loaded with paclitaxel (PTX-chit-SeNPs) were studied. These selenium nanoparticles were tested for drug release analysis at a pH of 7.4 and 5.5, and further characterized using FTIR, DLS, zeta potential, and TEM to confirm their morphology, and the encapsulation of the drug was carried out using UPLC analysis. Quantitative evaluation of anti-cancer properties was performed via MTT analysis, apoptosis, gene expression analysis, cell cycle arrest, and over-production of ROS. The unique combination of phytochemicals from the seed extract, chitosan, paclitaxel, and selenium nanoparticles can be effectively utilized to combat cancerous cells. The production of the nanosystem has been demonstrated to be cost-effective and have unique characteristics, and can be utilized for improving future diagnostic approaches.

Gold Nanoparticle-Incorporated Chitosan Nanogels as a Theranostic Nanoplatform for CT Imaging and Tumour Chemotherapy

Purpose

The translation of nanocarrier-based theranostics into cancer treatment is limited by their poor cellular uptake, low drug-loading capacity, uncontrolled drug release, and insufficient imaging ability.

Methods

In this study, novel hybrid nanogels were fabricated as theranostic nanocarriers by modifying chitosan (CTS)/tripolyphosphate (TPP) nanoparticles (NPs) with polyacrylic acid (PAA) and further conjugating cysteine-functionalized gold nanoparticles (AuNPs).

Results

The resultant nanogels, referred to as CTS/TPP/PAA@AuNPs (CTPA), exhibited excellent colloidal stability and a high encapsulation rate of 87% for the cationic drug doxorubicin (DOX). In the tumour microenvironment, the acidic pH and overexpression of lysozyme triggered CTPA@DOX to degrade and emit smaller nanoblocks (30–40 nm), which sequentially released the drug in a tumour-responsive manner. Cellular uptake experiments demonstrated that CTPA facilitates the entry of DOX into the cytoplasm. Furthermore, as visualised through AuNP-mediated computed tomography (CT) imaging, CTPA@DOX enabled favourable accumulation in the tumour. Our in vitro and in vivo data demonstrated that CTPA enabled advanced tumour cell-targeting delivery of DOX, which showed greater anti-tumour activity and biosafety than free DOX.

Conclusion

The natural polymer CTS was developed for degradable nanogels, which can precisely track drugs with high antitumour activity. Additionally, the surface adjustment strategy can be assembled to achieve cationic drug loading and high drug-loading capacity, controlled drug release, and sufficient imaging ability. Therefore, multifunctional CTPA enables efficient drug delivery and CT imaging, which is expected to provide a valuable strategy for designing advanced theranostic systems.

Chitosan-functionalized nanostructured lipid carriers containing chloroaluminum phthalocyanine for photodynamic therapy of skin cancer

The objective of this study was to obtain optimized nanostructured lipid carriers (NLC) functionalized with chitosan containing chloroaluminum phthalocyanine (ClAlPc) as a photosensitizer. Initially, the optimization of the preparation method of the NLC was performed, where the influence of different surfactants such as PVA and Tween 80, as well as different solid lipids such as stearic acid and Glycerol Monostearate (GM) was evaluated. The formulation containing GM and PVA (NLC10) was considered promising. Following, by the adsorption method (NLC10q), the formulation was functionalized with chitosan and characterized. NLC10 and NLC10q presented sizes of 131.5 and 231.5 nm, and ZP of -24.30 and + 19.96 mV, respectively. The encapsulation efficiency of NLC10q was 96 %, higher than NLC10 (79 %). The formulations were able to promote significant cutaneous retention of ClAlPc, after 2 h and 4 h of the study, and showed to be non-toxic to fibroblasts (biocompatible). PDT in BF16-F10 melanoma resulted in reduced cell viability to 70 % and 50 % for NLC10 and NLCq, respectively. In view of the results obtained, NLC showed to be promising in the treatment of skin cancer through PDT. NLC10q showed higher encapsulation efficiency and stability than NLC10, but, contrary to what was expected, it presented lower photodynamic efficiency.

Chitosan Nanoparticles: A Versatile Platform for Biomedical Applications

Chitosan is a biodegradable and biocompatible natural polymer that has been extensively explored in recent decades. The Food and Drug Administration has approved chitosan for wound treatment and nutritional use. Furthermore, chitosan has paved the way for advancements in different biomedical applications including as a nanocarrier and tissue-engineering scaffold. Its antibacterial, antioxidant, and haemostatic properties make it an excellent option for wound dressings. Because of its hydrophilic nature, chitosan is an ideal starting material for biocompatible and biodegradable hydrogels. To suit specific application demands, chitosan can be combined with fillers, such as hydroxyapatite, to modify the mechanical characteristics of pH-sensitive hydrogels. Furthermore, the cationic characteristics of chitosan have made it a popular choice for gene delivery and cancer therapy. Thus, the use of chitosan nanoparticles in developing novel drug delivery systems has received special attention. This review aims to provide an overview of chitosan-based nanoparticles, focusing on their versatile properties and different applications in biomedical sciences and engineering.

Recent Advances of Chitosan Formulations in Biomedical Applications

Chitosan, a naturally abundant cationic polymer, is chemically composed of cellulose-based biopolymers derived by deacetylating chitin. It offers several attractive characteristics such as renewability, hydrophilicity, biodegradability, biocompatibility, non-toxicity, and a broad spectrum of antimicrobial activity towards gram-positive and gram-negative bacteria as well as fungi, etc., because of which it is receiving immense attention as a biopolymer for a plethora of applications including drug delivery, protective coating materials, food packaging films, wastewater treatment, and so on. Additionally, its structure carries reactive functional groups that enable several reactions and electrochemical interactions at the biomolecular level and improves the chitosan’s physicochemical properties and functionality. This review article highlights the extensive research about the properties, extraction techniques, and recent developments of chitosan-based composites for drug, gene, protein, and vaccine delivery applications. Its versatile applications in tissue engineering and wound healing are also discussed. Finally, the challenges and future perspectives for chitosan in biomedical applications are elucidated.

Composite Coatings of Chitosan and Silver Nanoparticles Obtained by Galvanic Deposition for Orthopedic Implants

In this work, composite coatings of chitosan and silver nanoparticles were presented as an antibacterial coating for orthopedic implants. Coatings were deposited on AISI 304L using the galvanic deposition method. In galvanic deposition, the difference of the electrochemical redox potential between two metals (the substrate and a sacrificial anode) has the pivotal role in the process. In the coupling of these two metals a spontaneous redox reaction occurs and thus no external power supply is necessary. Using this process, a uniform deposition on the exposed area and a good adherence of the composite coating on the metallic substrate were achieved. Physical-chemical characterizations were carried out to evaluate morphology, chemical composition, and the presence of silver nanoparticles. These characterizations have shown the deposition of coatings with homogenous and porous surface structures with silver nanoparticles incorporated and distributed into the polymeric matrix. Corrosion tests were also carried out in a simulated body fluid at 37 °C in order to simulate the same physiological conditions. Corrosion potential and corrosion current density were obtained from the polarization curves by Tafel extrapolation. The results show an improvement in protection against corrosion phenomena compared to bare AISI 304L. Furthermore, the ability of the coating to release the Ag⁺ was evaluated in the simulated body fluid at 37 °C and it was found that the release mechanism switches from anomalous to diffusion controlled after 3 h.

Physical, Chemical, and Biological Properties of Chitosan-Coated Alginate Microparticles Loaded with Porcine Interleukin-1β: A Potential Protein Adjuvant Delivery System

We previously developed chicken interleukin-1β (IL-1β) mutants as single-dose adjuvants that induce protective immunity when co-administered with an avian vaccine. However, livestock such as pigs may require a vaccine adjuvant delivery system that provides long-lasting protection to reduce the need for successive booster doses. Therefore, we developed chitosan-coated alginate microparticles as a carrier for bovine serum albumin (BSA) or porcine IL-1β (pIL-1β) and assessed their physical, chemical, and biological properties. Electrospraying of the BSA-loaded alginate microparticles (BSA/ALG MPs) resulted in an encapsulation efficiency of 50%, and those MPs were then coated with chitosan (BSA/ALG/CHI MPs). Optical and scanning electron microscopy, zeta potential analysis, and Fourier transform infrared spectroscopy were used to characterize these MPs. The BSA encapsulation parameters were applied to ALG/CHI MPs loaded with pIL-1β, which were not cytotoxic to porcine fibroblasts but had enhanced bio-activity over unencapsulated pIL-1β. The chitosan layer of the BSA/ALG/CHI MPs prevented burst release and facilitated sustained release of pIL-1β for at least 28 days. In conclusion, BSA/ALG/CHI MPs prepared as a carrier for pIL-1β may be used as an adjuvant for the formulation of pig vaccines.

Progress in Research of Chitosan Chemical Modification Technologies and Their Applications

Chitosan, which is derived from chitin, is the only known natural alkaline cationic polymer. Chitosan is a biological material that can significantly improve the living standard of the country. It has excellent properties such as good biodegradability, biocompatibility, and cell affinity, and has excellent biological activities such as antibacterial, antioxidant, and hemostasis. In recent years, the demand has increased significantly in many fields and has huge application potential. Due to the poor water solubility of chitosan, its wide application is limited. However, chemical modification of the chitosan matrix structure can improve its solubility and biological activity, thereby expanding its application range. The review covers the period from 1996 to 2022 and was elaborated by searching Google Scholar, PubMed, Elsevier, ACS publications, MDPI, Web of Science, Springer, and other databases. The various chemical modification methods of chitosan and its main activities and application research progress were reviewed. In general, the modification of chitosan and the application of its derivatives have had great progress, such as various reactions, optimization of conditions, new synthetic routes, and synthesis of various novel multifunctional chitosan derivatives. The chemical properties of modified chitosan are usually better than those of unmodified chitosan, so chitosan derivatives have been widely used and have more promising prospects. This paper aims to explore the latest progress in chitosan chemical modification technologies and analyze the application of chitosan and its derivatives in various fields, including pharmaceuticals and textiles, thus providing a basis for further development and utilization of chitosan.

Synthesis, characterization, and evaluation of the antifungal properties of tissue conditioner incorporated with essential oils-loaded chitosan nanoparticles

Purpose

This study aims to investigate new tissue conditioner (TC) formulations involving chitosan nanoparticles (CSNPs) and essential oils (EO) for their antifungal potential, release kinetics, and hardness.

Materials and methods

CSNPs were synthesized, and the separate solutions of CSNP were prepared with two types of EO, i.e., Oregano oil and Lemongrass. The EO was loaded separately in two concentrations (200 μL and 250 μL). The blank and EO-loaded CSNPs were screened against Candida albicans (C. albicans), and their minimum inhibitory concentration was established. GC Reline^™ (GC corporation, USA) TC was considered a control group, whereby the four experimental groups were prepared by mixing CSNPs/EO solutions with TC powder. The antifungal effectiveness (C. albicans) and release kinetics behavior (1–6 h, 24 h, 48 h, and 72 h) was investigated. The Shore A hardness of control and experimental groups was evaluated in dry and wet modes (deionized water and artificial saliva). For statistical analysis, SPSS version 22 was used to do a one-way ANOVA post-hoc Tukey’s test.

Results

Compared to the control group, TCs containing blank CSNPs and CSNPs loaded with EO showed 3 and 5 log reductions in C. albicans growth, respectively. A significantly high antifungal effect was observed with TC containing lemongrass essential oil (200 μL). The continuous release of EO was detected for the first 6 hours, whereas completely stopped after 48 hours. Mean hardness values were highest for dry samples and lowest for samples stored in artificial saliva. The statistically significant difference within and between the study groups was observed in mean and cumulative essential oils release and hardness values of TCs over observed time intervals irrespective of storage media.

Conclusion

TCs containing essential-oil-loaded CSNPs seem a promising alternative treatment of denture-induced stomatitis, however, a further biological analysis should be taken.

The applications of polysaccharides in dentistry

Polysaccharides are natural polymers widely present in animals, plants, and several microorganisms. Polysaccharides have remarkable properties, including easy extractions, degradability, and renewability, and have no apparent toxicity, making them ideal for biomedical applications. Moreover, polysaccharides are suitable for repairing oral tissue defects and treating oral diseases due to their excellent biocompatibility, biosafety, anti-inflammatory, and antibacterial properties. The oral cavity is a relatively complex environment vulnerable to numerous conditions, including soft tissue diseases, hard tissue disorders, and as well as soft and hard tissue diseases, all of which are complex to treat. In this article, we reviewed different structures of natural polysaccharides with high commercial values and their applications in treating various oral disease, such as drug delivery, tissue regeneration, material modification, and tissue repair.

More than Antibiotics: Latest Therapeutics in the Treatment and Prevention of Ocular Surface Infections

Ocular surface infections have been common issues for ophthalmologists for decades. Traditional strategies for infection include antibiotics, antiviral agents, and steroids. However, multiple drug-resistant bacteria have become more common with the prevalence of antibiotic use. Furthermore, an ideal treatment for an infectious disease should not only emphasize eliminating the microorganism but also maintaining clear and satisfying visual acuity. Immunogenetic inflammation, tissue fibrosis, and corneal scarring pose serious threats to vision, and they are not attenuated or prevented by traditional antimicrobial therapeutics. Herein, we collected information about current management techniques including stem-cell therapy, probiotics, and gene therapy as well as preventive strategies related to Toll-like receptors. Finally, we will introduce the latest research findings in ocular drug-delivery systems, which may enhance the bioavailability and efficiency of ocular therapeutics. The clinical application of improved delivery systems and novel therapeutics may support people suffering from ocular surface infections.

Drug-Loaded Polymeric Particulated Systems for Ophthalmic Drugs Release

Drug delivery to the anterior or posterior segments of the eye is a major challenge due to the protection barriers and removal mechanisms associated with the unique anatomical and physiological nature of the ocular system. The paper presents the preparation and characterization of drug-loaded polymeric particulated systems based on pre-emulsion coated with biodegradable polymers. Low molecular weight biopolymers (chitosan, sodium hyaluronate and heparin sodium) were selected due to their ability to attach polymer chains to the surface of the growing system. The particulated systems with dimensions of 190–270 nm and a zeta potential varying from −37 mV to +24 mV depending on the biopolymer charges have been obtained. Current studies show that particles release drugs (dexamethasone/pilocarpine/bevacizumab) in a safe and effective manner, maintaining therapeutic concentration for a longer period of time. An extensive modeling study was performed in order to evaluate the drug release profile from the prepared systems. In a multifractal paradigm of motion, nonlinear behaviors of a drug delivery system are analyzed in the fractal theory of motion, in order to correlate the drug structure with polymer. Then, the functionality of a SL(2R) type ”hidden symmetry” implies, through a Riccati type gauge, different ”synchronization modes” (period doubling, damped oscillations, quasi-periodicity and intermittency) during the drug release process. Among these, a special mode of Kink type, better reflects the empirical data. The fractal study indicated more complex interactions between the angiogenesis inhibitor Bevacizumab and polymeric structure.

Culture and maintenance of neural progressive cells on cellulose acetate/graphene‑gold nanocomposites

In this study, the first CA nanofibers were fabricated by electrospinning under optimal conditions: flow rate of 0.5 ml/h, a voltage of 20 kV, electrospinning distance of 15 cm, and an internal temperature of 25 °C, and humidity of 38%. The used Graphene/gold nanoparticles for CA performance improvement were examined by TGA, XRD, and SEM analysis. Then the CA/graphene‑gold nanocomposite was synthesized under optimum electrospinning conditions: flow rate 3 ml/h, voltage 20 kV, electrospinning distance 15 cm, internal temperature 26 °C, and humidity 36%. The SEM images revealed that the nanofibers' thicknesses of Graphene‑gold NPs (CA₁) and Chitosan (CA₂) were 350 and 120 nm, respectively. The XRD diagrams of CA₀, CA₁ and CA₂ revealed the peaks at 2θ, 8°, and 21° with Miller indices of (001) and (110) are related to CA (CA₀), which proves its presence in other scaffolds. The FTIR analysis of samples indicated the presence of graphene‑gold NPs in scaffolding CA₁ and CA₂. The CA₂ nanofibers exhibited a high-water absorption capacity of about 2500% with the water contact-angle and Swelling method. The antibacterial properties of this nanocomposite were also confirmed by an antibacterial test on Staphylococcus aureus bacteria. The growth of Schwann cells on three scaffolds showed the highest growth of cells on CA₁ scaffolds.

The Use of Chitosan-Coated Nanovesicles in Repairing Alcohol-Induced Damage of Liver Cells in Mice

Background and Objectives In the past few decades, the studies concerning the natural polysaccharide chitosan have been centered on a new direction: its hepatoprotective action. The aim of our study was to evaluate the influence of previously designed chitosan lipid vesicles on the liver damage induced by alcohol consumption in mice. Materials and Methods The study involved the oral administration of substances in one daily dose as follows: Group 1 (control): water; Group 2 (control alcohol): 5% alcohol in water; Group 3 (CHIT): 0.1 mL/10 g body weight chitosan solution in animals treated with alcohol; Group 4 (CHIT-ves): 0.1 mL/10 g body chitosan vesicles in animals treated with alcohol; Group 5 (AcA): 200 mg/kg body ascorbic acid in animals treated with alcohol. In order to evaluate liver damage after alcohol consumption, the following hematological parameters were tested: the activity of alanine aminotransferase, aspartate aminotransferase and lactate dehydrogenase; serum values of urea and creatinine; the phagocytic capacity of polymorphonuclear neutrophilsin peripheral blood;serum opsonic capacity;bactericidal capacity of peritoneal macrophages; and the activity of malondialdehyde, glutathione peroxidase, superoxide dismutase and lactate dehydrogenase. Results and Conclusions The treatment with chitosan vesicles decreased liver enzyme activity and reduced the oxidative stress disturbances in alcoholic mice, thus repairing the hepatic functional and structural damages. These beneficial activities of chitosan vesicles were comparable with ascorbic acid effects in alcoholic mice.

Potential role of chitosan, PLGA and iron oxide nanoparticles in Parkinson’s disease therapy

Background

Parkinson's disease (PD) is a debilitating disease that alters an individual's functionality. Parkinsonism is a complex symptom consisting of numerous motor and non-motor features, and although several disorders are responsible, PD remains the most important. Several theories have been proposed for the characteristic pathological changes, the most important of which is the loss of dopaminergic neurons associated with a reduced ability to perform voluntary movements. Many drugs have been developed over the years to treat the condition and prevent its progression, but drug delivery is still a challenge due to the blood–brain barrier, which prevents the passage of drugs into the central nervous system. However, with the advances in nanotechnology in the medical field, there is growing hope of overcoming this challenge.

Summary

Our review highlights the potential role of three commonly studied nanoparticles in laboratory-induced animal models of PD: chitosan, PLGA, and iron oxide nanoparticles as potential PD therapy in humans.

Water-soluble chlorin e6-hydroxypropyl chitosan as a high-efficiency photoantimicrobial agent against Staphylococcus aureus

The development of new antimicrobial agents is important to combat infections caused by pathogenic bacteria. Herein, Hydroxypropyl chitosan (HPCS), a hydrophilic modified product of chitosan (CS), was employed as a carrier of the photosensitizer chlorin e6 (Ce6) through an amide bond to obtain the products (HPCS-Ce6 conjugates) with a degree of substitution (DS) ranging from 2.95% to 5.25%. The UV-vis absorption spectra and 1H NMR spectra confirmed the successful synthesis of the products. The products have a better and more stable reactive oxygen species (ROS) generation capacity and higher bacterial affinity than Ce6. At a very low dose (1.8 μg/mL), the highest DS product (HPCS-Ce6-3) can effectively kill Staphylococcus aureus (S. aureus) under 660 nm irradiation. In addition, the HPCS-Ce6 conjugates showed high biocompatibility in the CCK-8 test. The HPCS-Ce6 conjugates could be a photodynamic antibacterial agent with good water solubility, high biocompatibility, and antibacterial activity.

Impact of Deacetylation Degree on Properties of Chitosan for Formation of Electrosprayed Nanoparticles

Biopolymer of natural origin as chitosan has been studied and applied widely in practice. In the pharmaceutical field, especially, chitosan nanoparticles have been researched for a variety of drug delivery systems. There are many factors influencing the success of the chitosan nanoparticle delivery system. Therein, the specific parameters to the physicochemical nature of chitosan greatly determine the efficiency of its drugs carrier. The degree of deacetylation (DD) of chitosan is one of those parameters. In this study, the influence of DD on chitosan properties was clarified to facilitate the preparation of nanoparticles by the electrospraying method. DD can affect the solubility, crystallinity, and surface tension of chitosan, but it cannot strongly impact the viscosity of chitosan solution as much as the molecular weight (Mv). From these results, M3 chitosan, owning a high DD of 86.70%, and crystalline index of 44%, was dissolved in acetic acid for the collection of electrosprayed nanoparticles. The M3 solution having low viscosity of under 50 mm2/s displayed the easy adjustment of the stable Taylor-cone droplet at the nozzle tip. Particularly, the M3 chitosan solution with a concentration of 1.5 wt.% in acetic acid of 90 wt.% concentration operated at the working condition of 12 kV voltage, a distance between the two electrodes of 10 cm created spherical particles with an average diameter of 338 nm, narrow size distribution. These chitosan nanoparticles can obtain the initial requirement for application as injectable drugs carrier.

A review on plant polysaccharide based on drug delivery system for construction and application, with emphasis on traditional Chinese medicine polysaccharide

Carbohydrate polymers with unique chemical composition, molecular weight and functional chemical groups show multiple potentials in drug delivery. Most carbohydrate polymers such as plant polysaccharides exhibit advantages of biodegradability, ease of modification, low immunogenicity and low toxicity. They can be conjugated, cross-linked or functionally modified, and then used as nanocarrier materials. Polysaccharide drug delivery system can avoid the phagocytosis of the reticuloendothelial system, prevent the degradation of biomolecules, and increase the bioavailability of small molecules, thus exerting effective therapeutic effects. Therefore, they have been fully explored. In this paper, we reviewed the construction methods of drug delivery systems based on carbohydrate polymers (astragalus polysaccharide, angelica polysaccharide, lycium barbarum polysaccharide, ganoderma lucidum polysaccharide, bletilla polysaccharide, glycyrrhiza polysaccharide, and epimedium polysaccharides, etc). The application of polysaccharide drug delivery systems to deliver small molecule chemotherapeutic drugs, gene drugs, and metal ion drugs was also briefly introduced. At the same time, the role of the polysaccharide drug delivery system in tumor treatment, targeted therapy, and wound healing was discussed. In addition, the research of polysaccharide delivery systems based on the therapeutic efficacy of traditional Chinese medicine was also summarized and prospected.

Cellulose filter paper immobilized α-glucosidase and its application to screening inhibitors from traditional Chinese medicine

In this study, α-glucosidase was successfully immobilized on cellulose filter paper and further applied to screening inhibitors from traditional Chinese medicines combined with CE analysis. For α-glucosidase immobilization, cellulose filter paper was used as the carrier and grafted with amino groups by coating chitosan, then α-glucosidase was covalently bonded on the amino-modified carrier via epoxy ring-opening reaction using polyethylene glycol diglycidyl ether as the crosslinker. Several parameters influencing the enzyme immobilization were optimized and the optimal values were enzyme concentration of 4 U mL^-1 , polyethylene glycol diglycidyl ether concentration of 1.25%, chitosan concentration of 7.5 mg mL^-1 , immobilization pH 7.0, crosslinking time of 4 h and immobilization time of 2 h. The immobilized α-glucosidase exhibited good batch-to-batch reproducibility (RSD = 2.1%, n = 5), excellent storage stability (73.5% of its initial activity after being stored at 4°C for 15 days) and reusability (75% of its initial activity after 10 repeated cycles). The Michaelis constant of immobilized α-glucosidase and half-maximal inhibitory concentration of acarbose were calculated to be 1.12 mM and 0.38 μM, respectively. Finally, the immobilized α-glucosidase was used for screening inhibitors from 14 kinds of Traditional Chinese Medicine extracts, and Sanguisorbae Radix showed the strongest inhibitory effect on α-glucosidase. This article is protected by copyright. All rights reserved.

Experimental study of β-TCP scaffold loaded with VAN/PLGA microspheres in the treatment of infectious bone defects

Antibiotic bone cement filling technology has been widely used in the treatment of infectious bone defects for decades. However, the current treatment requires multiple complicated procedures, which would lead to pain and financial burden for patients. Repairing bone defects and control infection at the same time is the pain spot of orthopaedic area. In this study, we develop a composite scaffold that aiming at effectively repair infectious bone defects simultaneously. Vancomycin hydrochloride(Van) /Poly(lactic-co-glycolic) acid(PLGA) microspheres prepared by double emulsion method were successfully loaded into β-tricalcium phosphate scaffold through electrostatic and physical crosslinking. Full characterization, including mechanical properties, biocompatibility, in vitro release profile and antibacterial properties of the composite scaffolds(CPSFs) were performed. The rabbit osteomyelitis model based on big hole and small hole methods was established. Pharmacodynamics study, including the local bacteriostatic and osteogenic ability were evaluated by X-ray, Micro-CT and histopathology at 4 months after surgery. These findings indicate that a reliable rabbit model of local bone defect infection successfully established by big hole approach. The CPSFs with significant histocompatibility and biocompatibility could sustained release vancomycin for extended duration. It exhibited great application potential in clinical aim at the indication of local infectious bone defects.

pH/Redox/Lysozyme-Sensitive Hybrid Nanocarriers With Transformable Size for Multistage Drug Delivery

The majority of current nanocarriers in cancer treatment fail to deliver encapsulated cargos to their final targets at therapeutic levels, which decreases the ultimate efficacy. In this work, a novel core–shell nanocarrier with a biodegradable property was synthesized for efficient drug release and subcellular organelle delivery. Initially, silver nanoparticles (AgNPs) were grafted with terminal double bonds originating from N, N′-bisacrylamide cystamine (BAC). Then, the outer coatings consisting of chitosan (CTS) and polyvinyl alcohol (PVA) were deposited on the surface of modified AgNPs using an emulsion method. To improve the stability, disulfide-containing BAC was simultaneously reintroduced to cross-link CTS. The as-prepared nanoparticles (CAB) possessed the desired colloidal stability and exhibited a high drug loading efficiency of cationic anticancer agent doxorubicin (DOX). Furthermore, CAB was tailored to transform their size into ultrasmall nanovehicles responding to weak acidity, high glutathione (GSH) levels, and overexpressed enzymes. The process of transformation was accompanied by sufficient DOX release from CAB. Due to the triple sensitivity, CAB enabled DOX to accumulate in the nucleus, leading to a great effect against malignant cells. In vivo assays demonstrated CAB loading DOX held excellent biosafety and superior antitumor capacity. Incorporating all the benefits, this proposed nanoplatform may provide valuable strategies for efficient drug delivery.

Red blood cell-hitchhiking mediated pulmonary delivery of ivermectin: Effects of nanoparticle properties

Recent studies have demonstrated that ivermectin (IVM) exhibits antiviral activity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative virus of coronavirus disease 2019 (COVID-19). However, the repurposing of IVM for the treatment of COVID-19 has presented challenges primarily due to the low IVM plasma concentration after oral administration, which was well below IC₅₀. Here, a red blood cell (RBC)-hitchhiking strategy was used for the targeted delivery of IVM-loaded nanoparticles (NPs) to the lung. IVM-loaded poly (lactic-co-glycolic acid) (PLGA) NPs (IVM-PNPs) and chitosan-coating IVM-PNPs (IVM-CSPNPs) were prepared and adsorbed onto RBCs. Both RBC-hitchhiked IVM-PNPs and IVM-CSPNPs could significantly enhance IVM delivery to lungs, improve IVM accumulation in lung tissue, inhibit the inflammatory responses and finally significantly alleviate the progression of acute lung injury. Specifically, the redistribution and circulation effects were related to the properties of NPs. RBC-hitchhiked cationic IVM-CSPNPs showed a longer circulation time, slower accumulation and elimination rates, and higher anti-inflammatory activities than RBC-hitchhiked anionic IVM-PNPs. Therefore, RBC-hitchhiking provides an alternative strategy to improve IVM pharmacokinetics and bioavailability for repurposing of IVM to treat COVID-19. Furthermore, according to different redistribution effects of different NPs, RBC-hitchhiked NPs may achieve various accumulation rates and circulation times for different requirements of drug delivery.

Synthesis and evaluation of chitosan based controlled release nanoparticles for the delivery of ticagrelor

The aim of this contemporary work was to formulate a controlled release mucoadhesive nanoparticle formulation for enhancing the oral bioavailability of Ticagrelor (TG), a BCS class IV drug, having low oral bioavailability of about 36%. The nanoparticles can act as efficient carriers for hydrophobic drugs, due to having high surface area and hence can improve their aqueous solubility due to their hydrophilic nature. The nanoparticles (NPs) of TG were formulated using chitosan (CH) as polymer and sodium tripolyphosphate (TPP) as cross-linker, by ionic gelation technique with varying concentrations of polymer with respect to TG and TPP. Characterization of prepared nanoparticles was carried out to assess zeta potential, size, shape, entrapment efficiency (EE) and loading capacity (LC), using zeta sizer, surface morphology and chemical compatibility analysis. Drug release was observed using UV-Spectrophotometer. By increasing concentration of CH the desired size of particles (106.9 nm), zeta potential (22.6 mv) and poly dispersity index (0.364) was achieved. In vitro profiles showed a controlled and prolonged release of TG in both lower pH-1.2 and neutral pH-7.4 mediums, with effective protection of entrapped TG in simulated gastric conditions. X-ray diffraction patterns (XRD) showed the crystalline nature of formed NPs. Hence, this effort showed that hydrophobic drugs can be effectively encapsulated in nanoparticulate systems to enhance their solubility and stability, ultimately improving their bioavailability and effectiveness with better patient compliance by reducing dosing frequencies as well.

Novel Chitosan Derivatives and Their Multifaceted Biological Applications

Chitosan is a rather attractive material, especially because of its bio-origins as well as generation from exoskeletal waste. As the mantle has been effectively transferred from chitin to chitosan, so has it been extrapolated to in-house synthesized novel chitosan derivatives. This review comprehensively lists the available novel chitosan derivatives (ChDs) and summarizes their biological applications. The fact that chitosan derivatives do comprise multifaceted biological applications is attested by the voluminous reports on their varied contributions. However, this review points out to the fact that there has been selective focus on bio functions such as antifungal, antioxidant, antibacterial, whereas other biomedical applications and antiviral applications remain relatively less explored. With their current functionality record, there is definitely no doubt that the plethora of synthesized ChDs will have a profound impact on the unexplored biological aspects. This review points out this lacuna as room for future exploration.

Structure-Property Relationship for Different Mesoporous Silica Nanoparticles and its Drug Delivery Applications: A Review

Mesoporous silica nanoparticles (MSNs) are widely used as a promising candidate for drug delivery applications due to silica’s favorable biocompatibility, thermal stability, and chemical properties. Silica’s unique mesoporous structure allows for effective drug loading and controlled release at the target site. In this review, we have discussed various methods of MSNs’ mechanism, properties, and its drug delivery applications. As a result, we came to the conclusion that more in vivo biocompatibility studies, toxicity studies, bio-distribution studies and clinical research are essential for MSN advancement.

Enhancing Stability and Mucoadhesive Properties of Chitosan Nanoparticles by Surface Modification with Sodium Alginate and Polyethylene Glycol for Potential Oral Mucosa Vaccine Delivery

Background: The present study aimed to fabricate surface-modified chitosan nanoparticles with two mucoadhesive polymers (sodium alginate and polyethylene glycol) to optimize their protein encapsulation efficiency, improve their mucoadhesion properties, and increase their stability in biological fluids. Method: Ionotropic gelation was employed to formulate chitosan nanoparticles and surface modification was performed at five different concentrations (0.05, 0.1, 0.2, 0.3, 0.4% w/v) of sodium alginate (ALG) and polyethylene glycol (PEG), with ovalbumin (OVA) used as a model protein antigen. The functional characteristics were examined by dynamic light scattering (DLS), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM)/scanning transmission electron microscopy (STEM). Stability was examined in the presence of simulated gastric and intestinal fluids, while mucoadhesive properties were evaluated by in vitro mucin binding and ex vivo adhesion on pig oral mucosa tissue. The impact of the formulation and dissolution process on the OVA structure was investigated by sodium dodecyl-polyacrylamide gel electrophoresis (SDS-PAGE) and circular dichroism (CD). Results: The nanoparticles showed a uniform spherical morphology with a maximum protein encapsulation efficiency of 81%, size after OVA loading of between 200 and 400 nm and zeta potential from 10 to 29 mV. An in vitro drug release study suggested successful nanoparticle surface modification by ALG and PEG, showing gastric fluid stability (4 h) and a 96 h sustained OVA release in intestinal fluid, with the nanoparticles maintaining their conformational stability (SDS-PAGE and CD analyses) after release in the intestinal fluid. An in vitro mucin binding study indicated a significant increase in mucin binding from 41 to 63% in ALG-modified nanoparticles and a 27–49% increase in PEG-modified nanoparticles. The ex vivo mucoadhesion showed that the powdered particles adhered to the pig oral mucosa. Conclusion: The ALG and PEG surface modification of chitosan nanoparticles improved the particle stability in both simulated gastric and intestinal fluids and improved the mucoadhesive properties, therefore constituting a potential nanocarrier platform for mucosal protein vaccine delivery.

Bioactive Chitosan-Based Organometallic Scaffolds for Tissue Engineering and Regeneration

Captivating achievements in developing advanced hybrid biostructures through integrating natural biopolymers with inorganic materials (e.g., metals and metalloids) have paved the way towards the application of bioactive organometallic scaffolds (OMSs) in tissue engineering and regenerative medicine (TERM). Of various biopolymers, chitosan (CS) has been used widely for the development of bioactive OMSs, in large part due to its unique characteristics (e.g., biocompatibility, biodegradability, surface chemistry, and functionalization potential). In integration with inorganic elements, CS has been used to engineer advanced biomimetic matrices to accommodate both embedded cells and drug molecules and serve as scaffolds in TERM. The use of the CS-based OMSs is envisioned to provide a new pragmatic potential in TERM and even in precision medicine. In this review, we aim to elaborate on recent achievements in a variety of CS/metal, CS/metalloid hybrid scaffolds, and discuss their applications in TERM. We also provide comprehensive insights into the formulation, surface modification, characterization, biocompatibility, and cytotoxicity of different types of CS-based OMSs.

Evaluation of the Mucoadhesive Properties of Chitosan-Based Microstructured Lipid Carrier (CH-MLC)

Different mucoadhesive systems have been studied in recent years to increase the residence time of the delivery systems and to prolong the release of the drug. The aim of this work was to evaluate the mucoadhesive properties of chitosan-based Microstructured Lipid Carrier (CH-MLC) with a new approach which requires chitosan and mucin to be compacted into a tablet and mucoadhesion to be assessed on a non-mucoadhesive substrate. This type of test showed that chitosan maintains a close bond with mucin even in the presence of a fluid and even encapsulated in microparticles. After this, using a bioreactor, the release of N-acetylcysteine (NAC) from the microparticles (NA-CH-MLC) through a layer of mucus mimicking the pathological conditions of a patient with cystic fibrosis was tested. The release of the active from NAC-CH-MLC demonstrated how the chitosan inside the microparticles acts as a penetration enhancer and how the microparticles can impart a prolonged release over time.

Chitosan Nanoparticle-Based System: A New Insight into the Promising Controlled Release System for Lung Cancer Treatment

Lung cancer has been recognized as one of the most often diagnosed and perhaps most lethal cancer diseases worldwide. Conventional chemotherapy for lung cancer-related diseases has bumped into various limitations and challenges, including non-targeted drug delivery, short drug retention period, low therapeutic efficacy, and multidrug resistance (MDR). Chitosan (CS), a natural polymer derived from deacetylation of chitin, and comprised of arbitrarily distributed β-(1-4)-linked d-glucosamine (deacetylated unit) and N-acetyl-d-glucosamine (acetylated unit) that exhibits magnificent characteristics, including being mucoadhesive, biodegradable, and biocompatible, has emerged as an essential element for the development of a nano-particulate delivery vehicle. Additionally, the flexibility of CS structure due to the free protonable amino groups in the CS backbone has made it easy for the modification and functionalization of CS to be developed into a nanoparticle system with high adaptability in lung cancer treatment. In this review, the current state of chitosan nanoparticle (CNP) systems, including the advantages, challenges, and opportunities, will be discussed, followed by drug release mechanisms and mathematical kinetic models. Subsequently, various modification routes of CNP for improved and enhanced therapeutic efficacy, as well as other restrictions of conventional drug administration for lung cancer treatment, are covered.