Anticancer and anti-inflammatory properties of chitin and chitosan oligosaccharides

Applications of Chitosan in Prevention and Treatment Strategies of Infectious Diseases

Chitosan is the most commonly investigated functional cationic biopolymer in a wide range of medical applications due to its promising properties such as biocompatibility, biodegradability, and bioadhesivity, as well as its numerous bioactive properties. Within the last three decades, chitosan and its derivatives have been investigated as biomaterials for drug and vaccine delivery systems, besides for their bioactive properties. Due to the functional groups in its structure, it is possible to tailor the delivery systems with desired properties. There has been a great interest in the application of chitosan-based systems also for the prevention and treatment of infectious diseases, specifically due to their antimicrobial, antiviral, and immunostimulatory effects. In this review, recent applications of chitosan in the prevention and treatment of infectious diseases are reviewed, and possibilities and limitations with regards to technical and regulatory aspects are discussed. Finally, the future perspectives on utilization of chitosan as a biomaterial are discussed.

5-Fluorouracil-loaded green chitosan nanoparticles/ guar gum nanocomposite hydrogel in controlled drug delivery

In recent years nanotechnologies have been applied to human health with promising results, especially in the field of drug delivery. Polymeric nanoparticles (NPs) have garnered much importance in controlled drug delivery owing to their size. Chitosan (Cs) is a well-recognized biopolymer and Cs NPs have been widely explored in drug delivery. Nonetheless, reports pertaining to green synthesis of Cs NPs are scarce. Thus, in this study, green synthesis of Cs NPs was accomplished from raw mango peel extract. Spherical Cs NPs with positively charged surface of 33.4 mV was accomplished by this process. Cs NPs, in varied content, were integrated in a guar gum network matrix resulting in a nanocomposite hydrogel. The mechanical and thermal stability of the hydrogel improved upon addition of Cs NPs. The hydrogel exhibited smart swelling, good antioxidant and anti-inflammatory propensities. Cs NPs encapsulating 5-Fluorouracil demonstrated a controlled release drug profile in the colorectum and the kinetics implied the anomalous nature of drug release mechanism. The exposure of the drug-loaded nanocomposite hydrogel displayed improved anticancer effects in HT-29 colon cancer cells. Taken altogether, this study puts forth the greater efficacy of Cs NPs in controlled drug delivery for anticancer therapy.

Genomic Exploration of a Chitinolytic Streptomyces albogriseolus PMB5 Strain from European mantis (Mantis religiosa)

The genus Streptomyces is renowned not only for its natural antibiotic production but also for its abundant chitinolytic enzymes, which break down stubborn chitin into chitooligosaccharides. Despite this, there have been limited studies utilizing whole-genome sequencing to explore the repertoire of chitin degradation and utilization genes in Streptomyces. A particularly compelling source of novel antimicrobials and enzymes lies in the microbiota of insects, where bacterial symbionts produce antimicrobials to protect against opportunistic pathogens and enzymes to adapt to the environment. In this study, we present the chitinolytic strain Streptomyces albogriseolus PMB5, isolated from the insectivorous Mantis religiosa (European mantis). Whole-genome sequencing revealed that PMB5 harbors a linear chromosome of 7,211,961 bp and a linear plasmid of 327,989 bp. The genome comprises 6683 genes, including 6592 protein-coding sequences and 91 RNA genes. Furthermore, genome analysis revealed 19 biosynthetic gene clusters covering polyketides, terpenes, and RiPPs, with 10 clusters showing significant gene similarity (>80%) to known clusters like antimycin, hopene, and geosmin. In the genome of S. albogriseolus PMB5, we were able to identify several antibiotic resistance genes; these included cml (resistance to phenicol), gimA (resistance to macrolides), parY (resistance to aminocoumarin), oleC/oleD (resistance to macrolides), novA (resistance to aminocoumarin) and bla/blc (resistance to beta-lactams). Additionally, three clusters displayed no similarity to known sequences, suggesting novel bioactive compound discovery potential. Remarkably, strain PMB5 is the first reported S. albogriseolus capable of thriving on a medium utilizing chitin as a carbon source, with over 50 chitin-utilizing genes identified, including five AA10 family LPMOs, five GH18 chitinases, and one GH19 chitinase. This study significantly enhances the genomic understanding of S. albogriseolus, a species previously underrepresented in research, paving the way to further exploration of the biotechnological potential of the species.

New Insights into Sources, Bioavailability, Health-Promoting Effects, and Applications of Chitin and Chitosan

Chitin and chitosan are mostly derived from the exoskeletons of crustaceans, insects, and fungi. Chitin is the second most abundant biopolymer after cellulose, and it is a fibrous polysaccharide which resists enzymatic degradation in the stomach but undergoes microbial fermentation in the colon, producing beneficial metabolites. Chitosan, which is more soluble in the alkaline small intestine, is more susceptible to enzymatic action. Both biopolymers show limited absorption into the bloodstream, with smaller particles exhibiting better bioavailability. The health effects include anti-inflammatory properties, potential in immune system modulation, impacts on cholesterol levels, and antimicrobial effects, with a specific focus on implications for gut health. Chitin and chitosan exhibit anti-inflammatory properties by interacting with immune cells, influencing cytokine production, and modulating immune responses, which may benefit conditions characterized by chronic inflammation. These biopolymers can impact cholesterol levels by binding to dietary fats and reducing lipid absorption. Additionally, their antimicrobial properties contribute to gut health by controlling harmful pathogens and promoting beneficial gut microbiota. This review explores the extensive health benefits and applications of chitin and chitosan, providing a detailed examination of their chemical compositions, dietary sources, and applications, and critically assessing their health-promoting effects in the context of human well-being.

The Role of Inhaled Chitosan-Based Nanoparticles in Lung Cancer Therapy

Lung cancer is the leading cause of cancer-related mortality worldwide, largely due to the limited efficacy of anticancer drugs, which is primarily attributed to insufficient doses reaching the lungs. Additionally, patients undergoing treatment experience severe systemic adverse effects due to the distribution of anticancer drugs to non-targeted sites. In light of these challenges, there has been a growing interest in pulmonary administration of drugs for the treatment of lung cancer. This route allows drugs to be delivered directly to the lungs, resulting in high local concentrations that can enhance antitumor efficacy while mitigating systemic toxic effects. However, pulmonary administration poses the challenge of overcoming the mechanical, chemical, and immunological defenses of the respiratory tract that prevent the inhaled drug from properly penetrating the lungs. To overcome these drawbacks, the use of nanoparticles in inhaler formulations may be a promising strategy. Nanoparticles can assist in minimizing drug clearance, increasing penetration into the lung epithelium, and enhancing cellular uptake. They can also facilitate increased drug stability, promote controlled drug release, and delivery to target sites, such as the tumor environment. Among them, chitosan-based nanoparticles demonstrate advantages over other polymeric nanocarriers due to their unique biological properties, including antitumor activity and mucoadhesive capacity. These properties have the potential to enhance the efficacy of the drug when administered via the pulmonary route. In view of the above, this paper provides an overview of the research conducted on the delivery of anticancer drug-loaded chitosan-based nanoparticles incorporated into inhaled drug delivery devices for the treatment of lung cancer. Furthermore, the article addresses the use of emerging technologies, such as siRNA (small interfering RNA), in the context of lung cancer therapy. Particularly, recent studies employing chitosan-based nanoparticles for siRNA delivery via the pulmonary route are described.

Eco-friendly and safe alternatives for the valorization of shrimp farming waste

The seafood industry generates waste, including shells, bones, intestines, and wastewater. The discards are nutrient-rich, containing varying concentrations of carotenoids, proteins, chitin, and other minerals. Thus, it is imperative to subject seafood waste, including shrimp waste (SW), to secondary processing and valorization for demineralization and deproteination to retrieve industrially essential compounds. Although several chemical processes are available for SW processing, most of them are inherently ecotoxic. Bioconversion of SW is cost-effective, ecofriendly, and safe. Microbial fermentation and the action of exogenous enzymes are among the significant SW bioconversion processes that transform seafood waste into valuable products. SW is a potential raw material for agrochemicals, microbial culture media, adsorbents, therapeutics, nutraceuticals, and bio-nanomaterials. This review comprehensively elucidates the valorization approaches of SW, addressing the drawbacks of chemically mediated methods for SW treatments. It is a broad overview of the applications associated with nutrient-rich SW, besides highlighting the role of major shrimp-producing countries in exploring SW to achieve safe, ecofriendly, and efficient bio-products.

Advances in the preparation, characterization, and biological functions of chitosan oligosaccharide derivatives: A review

Chitosan oligosaccharide (COS), which represent the positively charged basic amino oligosaccharide in nature, is the deacetylated and degraded products of chitin. COS has become the focus of intensive scientific investigation, with a growing body of practical and clinical studies highlighting its remarkable health-enhancing benefits. These effects encompass a wide range of properties, including antibacterial, antioxidant, anti-inflammatory, and anti-tumor activities. With the rapid advancements in chemical modification technology for oligosaccharides, many COS derivatives have been synthesized and investigated. These newly developed derivatives possess more stable chemical structures, improved biological activities, and find applications across a broader spectrum of fields. Given the recent interest in the chemical modification of COS, this comprehensive review seeks to consolidate knowledge regarding the preparation methods for COS derivatives, alongside discussions on their structural characterization. Additionally, various biological activities of COS derivatives have been discussed in detail. Lastly, the potential applications of COS derivatives in biomedicine have been reviewed and presented.

Role of Natural Binding Proteins in Therapy and Diagnostics

This review systematically investigates the critical role of natural binding proteins (NBPs), encompassing DNA-, RNA-, carbohydrate-, fatty acid-, and chitin-binding proteins, in the realms of oncology and diagnostics. In an era where cancer continues to pose significant challenges to healthcare systems worldwide, the innovative exploration of NBPs offers a promising frontier for advancing both the diagnostic accuracy and therapeutic efficacy of cancer management strategies. This manuscript provides an in-depth examination of the unique mechanisms by which NBPs interact with specific molecular targets, highlighting their potential to revolutionize cancer diagnostics and therapy. Furthermore, it discusses the burgeoning research on aptamers, demonstrating their utility as 'nucleic acid antibodies' for targeted therapy and precision diagnostics. Despite the promising applications of NBPs and aptamers in enhancing early cancer detection and developing personalized treatment protocols, this review identifies a critical knowledge gap: the need for comprehensive studies to understand the diverse functionalities and therapeutic potentials of NBPs across different cancer types and diagnostic scenarios. By bridging this gap, this manuscript underscores the importance of NBPs and aptamers in paving the way for next-generation diagnostics and targeted cancer treatments.

Analysis of molecular structure and topological properties of chitosan isolated from crab shell and mushroom

This investigation aimed to scrutinize the chemical and structural analogies between chitosan extracted from crab exoskeleton (High Molecular Weight Chitosan, HMWC) and chitosan obtained from mushrooms (Mushroom-derived Chitosan, MRC), and to assess their biological functionalities. The resulting hydrolysates from the hydrolysis of HMWC by chitosanase were categorized as chitosan oligosaccharides (csCOS), while those from MRC were denoted as mrCOS. The molecular weights (MW) of csCOS and mrCOS were determined using Matrix-Assisted Laser Desorption Ionization Time-of-Flight (MALDI-TOF) mass spectrometry. Furthermore, structural resemblances of csCOS and mrCOS were assessed utilizing X-ray powder diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopy. Intriguingly, no apparent structural disparity between csCOS and mrCOS was noted in terms of the glucosamine (GlcN) and N-acetylglucosamine (GlcNAc) composition ratios. Consequently, the enzymatic activities of chitosanase for HMWC and MRC exhibited remarkable similarity. A topological examination was performed between the enzyme and the substrate to deduce the alteration in MW of COSs following enzymatic hydrolysis. Moreover, the evaluation of antioxidant activity for each COS revealed insignificance in the structural disparity between HMWC and MRC. In summary, grounded on the chemical structural similarity of HMWC and MRC, we propose the potential substitution of HMWC with MRC, incorporating diverse biological functionalities.

Chitosan-based materials for dental implantology: A comprehensive review

Chitosan, a versatile biopolymer, has gained recognition in the discipline of dental implantology due to possessing salient properties. This comprehensive review explores the potential of chitosan in dental implants, focusing on its biocompatibility, bioactivity, and the various chitosan-based materials that have been utilized for dental implant therapy. The review also highlights the importance of surface treatment in dental implants to enhance osseointegration and inhibit bacterial biofilm formation. Additionally, the chemical structure, properties, and sources of chitosan are described, along with its different structural forms. The characteristics of chitosan particularly color, molecular weight, viscosity, and degree of deacetylation are discussed about their influence on its applications. This review provides valuable insights into the promising utilization of polymeric chitosan in enhancing the success and functionality of dental implants. This study highlights the potential applications of chitosan in oral implantology. Chitosan possesses various advantageous properties, including muco-adhesiveness, hemostatic action, biocompatibility, biodegradability, bioactivity, and antibacterial and antifungal activities, which enhance its uses in dental implantology. However, it has limited aqueous solubility at the physiological pH, which sometimes restricts its biological application, but this problem can be overcome by using modified chitosan or chitosan derivatives, which have also shown encouraging results. Recent research suggests that chitosan may act as a promising material for coating titanium-based implants, improving osteointegration together with antibacterial properties.

Advancements in application of chitosan and cyclodextrins in biomedicine and pharmaceutics: recent progress and future trends

The global community is faced with numerous health concerns such as cancer, cardiovascular and neurological diseases, diabetes, joint pain, osteoporosis, among others. With the advancement of research in the fields of materials chemistry and medicine, pharmaceutical technology and biomedical analysis have entered a new stage of development. The utilization of natural oligosaccharides and polysaccharides in pharmaceutical/biomedical studies has gained significant attention. Over the past decade, several studies have shown that chitosan and cyclodextrin have promising biomedical implications in background analysis, ongoing development, and critical applications in biomedical and pharmaceutical research fields. This review introduces different types of saccharides/natural biopolymers such as chitosan and cyclodextrin and discusses their wide-ranging applications in the biomedical/pharmaceutical research area. Recent research advances in pharmaceutics and drug delivery based on cyclodextrin, and their response to smart stimuli, as well as the biological functions of cyclodextrin and chitosan, such as the immunomodulatory effects, antioxidant, and antibacterial properties, have also been discussed, along with their applications in tissue engineering, wound dressing, and drug delivery systems. Finally, the innovative applications of chitosan and cyclodextrin in the pharmaceutical/biomedicine were reviewed, and current challenges, research/technological gaps, and future development opportunities were surveyed.

Chitin-mediated blockade of chitinase-like proteins reduces tumor immunosuppression, inhibits lymphatic metastasis and enhances anti-PD-1 efficacy in complementary TNBC models

BACKGROUND

Chitinase-like proteins (CLPs) play a key role in immunosuppression under inflammatory conditions such as cancer. CLPs are enzymatically inactive and become neutralized upon binding of their natural ligand chitin, potentially reducing CLP-driven immunosuppression. We investigated the efficacy of chitin treatment in the context of triple-negative breast cancer (TNBC) using complementary mouse models. We also evaluated the immunomodulatory influence of chitin on immune checkpoint blockade (ICB) and compared its efficacy as general CLP blocker with blockade of a single CLP, i.e. chitinase 3-like 1 (CHI3L1).

METHODS

Female BALB/c mice were intraductally injected with luciferase-expressing 4T1 or 66cl4 cells and systemically treated with chitin in combination with or without anti-programmed death (PD)-1 ICB. For single CLP blockade, tumor-bearing mice were treated with anti-CHI3L1 antibodies. Metastatic progression was monitored through bioluminescence imaging. Immune cell changes in primary tumors and lymphoid organs (i.e. axillary lymph nodes and spleen) were investigated through flow cytometry, immunohistochemistry, cytokine profiling and RNA-sequencing. CHI3L1-stimulated RAW264.7 macrophages were subjected to 2D lymphatic endothelial cell adhesion and 3D lymphatic integration in vitro assays for studying macrophage-mediated lymphatic remodeling.

RESULTS

Chitin significantly reduced primary tumor progression in the 4T1-based model by decreasing the high production of CLPs that originate from tumor-associated neutrophils (TANs) and Stat3 signaling, prominently affecting the CHI3L1 and CHI3L3 primary tumor levels. It reduced immunosuppressive cell types and increased anti-tumorigenic T-cells in primary tumors as well as axillary lymph nodes. Chitin also significantly reduced CHI3L3 primary tumor levels and immunosuppression in the 66cl4-based model. Compared to anti-CHI3L1, chitin enhanced primary tumor growth reduction and anti-tumorigenicity. Both treatments equally inhibited lymphatic adhesion and integration of macrophages, thereby hampering lymphatic tumor cell spreading. Upon ICB combination therapy, chitin alleviated anti-PD-1 resistance in both TNBC models, providing a significant add-on reduction in primary tumor and lung metastatic growth compared to chitin monotherapy. These add-on effects occurred through additional increase in CD8α+ T-cell infiltration and activation in primary tumor and lymphoid organs.

CONCLUSIONS

Chitin, as a general CLP blocker, reduces CLP production, enhances anti-tumor immunity as well as ICB responses, supporting its potential clinical relevance in immunosuppressed TNBC patients.

Chitin: A versatile biopolymer-based functional therapy for cartilage regeneration

Chitin is the second most abundant biopolymer and its inherent biological characteristics make it ideal to use for tissue engineering. For many decades, its properties like non-toxicity, abundant availability, ease of modification, biodegradability, biocompatibility, and anti-microbial activity have made chitin an ideal biopolymer for drug delivery. Research studies have also shown many potential benefits of chitin in the formulation of functional therapy for cartilage regeneration. Chitin and its derivatives can be processed into 2D/3D scaffolds, hydrogels, films, exosomes, and nano-fibers, which make it a versatile and functional biopolymer in tissue engineering. Chitin is a biomimetic polymer that provides targeted delivery of mesenchymal stem cells, especially of chondrocytes at the injected donor sites to accelerate regeneration by enhancing cell proliferation and differentiation. Due to this property, chitin is considered an interesting polymer that has a high potential to provide targeted therapy in the regeneration of cartilage. Our paper presents an overview of the method of extraction, structure, properties, and functional role of this versatile biopolymer in tissue engineering, especially cartilage regeneration.

Multi-functional pH-responsive and biomimetic chitosan-based nanoplexes for targeted delivery of ciprofloxacin against bacterial sepsis

Bacterial sepsis is a mortal syndromic disease characterized by a complex pathophysiology that hinders effective targeted therapy. This study aimed to develop multifunctional, biomimetic and pH-responsive ciprofloxacin-loaded chitosan (CS)/sodium deoxycholic acid (SDC) nanoplexes (CS/SDC) nanoplexes with the ability to target and modulate the TLR4 pathway, activated during sepsis. The formulated nanoplexes were characterized in terms of physicochemical properties, in silico and in vitro potential biological activities. The optimal formulation showed good biocompatibility and stability with appropriate physicochemical parameters. The surface charge changed from negative at pH 7.4 to positive at pH 6.0 accompanied with a significantly faster release of CIP at pH 6.0 compared to 7.4. The biomimicry was elucidated by in silico tools and MST and results confirmed strong binding between the system and TLR4. Furthermore, the system revealed 4- and 2-fold antibacterial enhancement at acidic pH, and 3- and 4-fold better antibiofilm efficacy against Methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa (P. aeruginosa) respectively, compared to bare CIP. In addition, enhanced bacterial efflux pump inhibition was demonstrated by CS/SDC nanoplexes. Finally, the developed nanosystem showed excellent antioxidant activity against DPPH radicals. Taken together, the study confirmed the multi-functionalities of CS/SDC nanoplexes and their potential benefits in improving bacterial sepsis therapy.

Use of Biomaterials in 3D Printing as a Solution to Microbial Infections in Arthroplasty and Osseous Reconstruction

The incidence of microbial infections in orthopedic prosthetic surgeries is a perennial problem that increases morbidity and mortality, representing one of the major complications of such medical interventions. The emergence of novel technologies, especially 3D printing, represents a promising avenue of development for reducing the risk of such eventualities. There are already a host of biomaterials, suitable for 3D printing, that are being tested for antimicrobial properties when they are coated with bioactive compounds, such as antibiotics, or combined with hydrogels with antimicrobial and antioxidant properties, such as chitosan and metal nanoparticles, among others. The materials discussed in the context of this paper comprise beta-tricalcium phosphate (β-TCP), biphasic calcium phosphate (BCP), hydroxyapatite, lithium disilicate glass, polyetheretherketone (PEEK), poly(propylene fumarate) (PPF), poly(trimethylene carbonate) (PTMC), and zirconia. While the recent research results are promising, further development is required to address the increasing antibiotic resistance exhibited by several common pathogens, the potential for fungal infections, and the potential toxicity of some metal nanoparticles. Other solutions, like the incorporation of phytochemicals, should also be explored. Incorporating artificial intelligence (AI) in the development of certain orthopedic implants and the potential use of AI against bacterial infections might represent viable solutions to these problems. Finally, there are some legal considerations associated with the use of biomaterials and the widespread use of 3D printing, which must be taken into account.

Comprehensive Review on Herbal Medicine: Emphasis on Current Therapy and Role of Phytoconstituents for Cancer Treatment

INTRODUCTION

Cancer poses a significant public health challenge in both developed and developing nations, with a rising global incidence of patients facing the threat of death due to abnormal cell proliferation.

AIM

Review explores the utilization of different parts of herbal medicinal plants and their active pharmaceutical constituents in the prevention and treatment of various types of cancer.

METHODOLOGY

Various anticancer medicinal plants have been identified, demonstrating their therapeutic effects by inhibiting cancer-stimulating enzymes and hormones, activating DNA repair processes, boosting the synthesis of protective stimulants, reducing the formation of free radicals, and enhancing individual immunity. Data for this study were gathered from diverse online bibliographic and databases, including Google, Google Scholar, Mendeley, Springer Link, Research Gate, and PubMed.

RESULT

Herbal drugs have a huge contribution to the inhibition of the progression of cancer.A large volume of clinical studies has reported the beneficial effects of herbal medicines on the survival, immune modulation, and quality of life (QOL) of cancer patients, when these herbal medicines are used in combination with conventional therapeutics.

CONCLUSION

The latest medicines for the clinical purpose (Above 50 %) are derived from herbal products. Furthermore, combination of these herbs with nanotechnology shows promise in treating specific carcinomas.

A Novel Phytotherapy Application: Preparation, Characterization, Antioxidant Activities and Determination of Anti-inflammatory Effects by In vivo HET-CAM Assay of Chitosan-based DDSs Containing Endemic Helichrysum pamphylicum P.H. Davis & Kupicha Methanolic Extract

BACKGROUND

Numerous pharmaceutical applications for chitosan, a polysaccharide made from the shells of crustaceans by deacetylating chitin that occurs naturally, are currently being researched. Chitosan, a natural polymer, is successfully used to prepare many drug-carrier systems, such as gel, film, nanoparticle, and wound dressing.

OBJECTIVE

Preparing chitosan gels without external crosslinkers is less toxic and environmentally friendly.

METHODS

Chitosan-based gels containing Helichrysum pamphylicum P.H. Davis & Kupicha methanolic extract (HP) were produced successfully.

RESULTS

The F9-HP coded gel prepared with high molecular weight chitosan was chosen as the optimum formulation in terms of pH and rheological properties. The amount of HP was found to be 98.83% ± 0.19 in the F9-HP coded formulation. The HP release from the F9-HP coded formula was determined to be slower and 9 hours prolonged release compared to pure HP. It was determined that HP release from F9-HP coded formulation with the DDSolver program was by anomalous (non-fickian) diffusion mechanism. The F9-HP coded formulation significantly showed DPPH free radical scavenger, ABTS•+ cation decolorizing and metal chelating antioxidant activity while weakly reducing antioxidant potential. According to the HET-CAM scores, strong anti-inflammatory activity was obtained by the F9-HP coded gel at a dose of 20 μg.embryo-1 (p<0.05 compared with SDS).

CONCLUSION

In conclusion, it can be said that chitosan-based gels containing HP, which can be used in both antioxidant and anti-inflammatory treatment, were successfully formulated and characterized.

Review on chitosan-based antibacterial hydrogels: Preparation, mechanisms, and applications

Chitosan (CS) is known for its remarkable properties, such as good biocompatibility, biodegradability, and renewability, in addition to its antibacterial and biological activities. However, as CS is insoluble in water, it displays limited antibacterial performance under neutral and physiological conditions. A viable solution to this problem is grafting chemically modified groups onto the CS framework, thereby increasing its solubility and enhancing its antibacterial effect. Herein, the antibacterial action mechanism of CS and its derivatives is reviewed, confirming the prevalent use of composite materials comprising CS and its derivatives as an antibacterial agent. Generally, the antimicrobial ability of CS-based biomaterials can be enhanced by incorporating supplementary polymers and antimicrobial agents. Research on CS-based composite biomaterials is ongoing and numerous types of biomaterials have been reported, including inorganic nanoparticles, antibacterial agents, and CS derivatives. The development of these composite materials has considerably expanded the application of CS-based antibacterial materials. This study reviews the latest progress in research regarding CS-based composite hydrogels for wound repair, tissue engineering, drug release, water purification, and three-dimensional printing applications. Finally, the summary and future outlook of CS-based antibacterial hydrogels are presented in anticipation of a broader range of applications of CS-based antibacterial hydrogels.

Chitotriose Enhanced Antitumor Activity of Doxorubicin through Egr1 Upregulation in MDA-MB-231 Cells

Dietary supplementation is proposed as a strategy to reduce the side effects of conventional chemotherapy for triple-negative breast cancer (TNBC). Chitosan oligosaccharides (COS), a functional carbohydrate, have been identified to potentially inhibit cancer cell proliferation. However, a detailed investigation is required to fully understand its exact influence, particularly in terms of COS composition. The antitumor activities of COS oligomers and its monomer of glucosamine, when combined with doxorubicin separately, were evaluated in MDA-MB-231 cells. Chitotriose was identified to have the most significant synergistic effect. Preincubation with chitotriose was observed to promote the entry of doxorubicin into the cell nuclei and induce morphological changes in the cells. Mechanism analysis at the transcriptional level revealed that the early growth response 1 (Egr1) gene was a key regulator in enhancing the suppressive effect. This gene was found to modulate the activity of its downstream gene, growth arrest, and DNA damage-inducible alpha (Gadd45a). The role of Egr1 was confirmed through a small interfering RNA test and function assay. These findings provide insight into the effect and underlying mechanism of chitotriose supplementation for TNBC therapy.

An overview of viral chitinases: General properties and biotechnological potential

Chitin is a biopolymer profusely present in nature and of pivotal importance as a structural component in cells. It is degraded by chitinases, enzymes naturally produced by different organisms. Chitinases are proteins enrolled in many cellular mechanisms, including the remodeling process of the fungal cell wall, the cell growth process, the autolysis of filamentous fungi, and cell separation of yeasts, among others. These enzymes also have properties with different biotechnological applications. They are used to produce polymers, for biological control, biofilm formation, and as antitumor and anti-inflammatory target molecules. Chitinases are classified into different glycoside hydrolase (GH) families and are widespread in microorganisms, including viruses. Among them, the GH18 family is highly predominant in the viral genomes, being present and active enzymes in baculoviruses and nucleocytoplasmic large DNA viruses (NCLDV), especially chloroviruses from the Phycodnaviridae family. These viral enzymes contain one or more GH domains and seem to be involved during the viral replication cycle. Curiously, only a few DNA viruses have these enzymes, and studying their properties could be a key feature for biological and biotechnological novelties. Here, we provide an overview of viral chitinases and their probable function in viral infection, showing evidence of at least two distinct origins for these enzymes. Finally, we discuss how these enzymes can be applied as biotechnological tools and what one can expect for the coming years on these GHs.

Progress in Nanostructured Mechano-Bactericidal Polymeric Surfaces for Biomedical Applications

Bacterial infections and antibiotic resistance remain significant contributors to morbidity and mortality worldwide. Despite recent advances in biomedical research, a substantial number of medical devices and implants continue to be plagued by bacterial colonisation, resulting in severe consequences, including fatalities. The development of nanostructured surfaces with mechano-bactericidal properties has emerged as a promising solution to this problem. These surfaces employ a mechanical rupturing mechanism to lyse bacterial cells, effectively halting subsequent biofilm formation on various materials and, ultimately, thwarting bacterial infections. This review delves into the prevailing research progress within the realm of nanostructured mechano-bactericidal polymeric surfaces. It also investigates the diverse fabrication methods for developing nanostructured polymeric surfaces with mechano-bactericidal properties. We then discuss the significant challenges associated with each approach and identify research gaps that warrant exploration in future studies, emphasizing the potential for polymeric implants to leverage their distinct physical, chemical, and mechanical properties over traditional materials like metals.

An In Vitro Study of Chitosan-Coated Bovine Pericardium as a Dural Substitute Candidate

Defects in the dura matter can be caused by head injury, and many cases require neurosurgeons to use artificial dura matter. Bovine pericardium is an option due to its abundant availability, adjustable size and characteristics, and because it has more collagen than porcine or equine pericardia. Nevertheless, the drawback of bovine pericardium is that it has a higher inflammatory effect than other synthetic dura matters. Chitosan has been shown to have a strong anti-inflammatory effect and has good tensile strength; thus, the idea was formulated to use chitosan as a coating for bovine pericardium. This study used decellularized bovine pericardial membranes with 0.5% sodium dodecyl sulphate and coatings containing chitosan at concentrations of 0.25%, 0.5%, 0.75%, and 1%. An FTIR test showed the presence of a C=N functional group as a bovine pericardium-chitosan bond. Morphological tests of the 0.25% and 0.5% chitosan concentrations showed standard pore sizes. The highest tensile strength percentage was shown by the membrane with a chitosan concentration of 1%. The highest degradation rate of the membrane was observed on the 7th and 14th days for 0.75% and 1% concentrations, and the lowest swelling ratio was observed for the 0.25% concentration. The highest level of cell viability was found for 0.75% chitosan. The bovine pericardium membrane with a 0.75% concentration chitosan coating was considered the optimal sample for use as artificial dura matter.

N-acetyl-d-glucosamine-based oligosaccharides from chitin: Enzymatic production, characterization and biological activities

Chitin, the second most abundant biopolymer, possesses diverse applications in the food, agricultural, and pharmaceutical industries due to its functional properties. However, the potential applications of chitin are limited owing to its high crystallinity and low solubility. N-acetyl chitooligosaccharides and lacto-N-triose II, the two types of GlcNAc-based oligosaccharides, can be obtained from chitin by enzymatic methods. With their lower molecular weights and improved solubility, these two types of GlcNAc-based oligosaccharides display more various beneficial health effects when compared to chitin. Among their abilities, they have exhibited antioxidant, anti-inflammatory, anti-tumor, antimicrobial, and plant elicitor activities as well as immunomodulatory and prebiotic effects, which suggests they have the potential to be utilized as food additives, functional daily supplements, drug precursors, elicitors for plants, and prebiotics. This review comprehensively covers the enzymatic methods used for the two types of GlcNAc-based oligosaccharides production from chitin by chitinolytic enzymes. Moreover, current advances in the structural characterization and biological activities of these two types of GlcNAc-based oligosaccharides are summarized in the review. We also highlight current problems in the production of these oligosaccharides and trends in their development, aiming to offer some directions for producing functional oligosaccharides from chitin.

Plant Protein-Peptide Supramolecular Polymers with Reliable Tissue Adhesion for Surgical Sealing

The fusion of protein science and peptide science opens up new frontiers in creating innovative biomaterials. Herein, a new kind of adhesive soft materials based on a natural occurring plant protein and short peptides via a simple co-assembly route are explored. The hydrophobic zein is supercharged by sodium dodecyl sulfate to form a stable protein colloid, which is intended to interact with charge-complementary short peptides via multivalent ionic and hydrogen bonds, forming adhesive materials at macroscopic level. The adhesion performance of the resulting soft materials can be fine-manipulated by customizing the peptide sequences. The adhesive materials can resist over 78 cmH2 O of bursting pressure, which is high enough to meet the sealing requirements of dural defect. Dural sealing and repairing capability of the protein-peptide biomaterials are further identified in rat and rabbit models. In vitro and in vivo assays demonstrate that the protein-peptide adhesive shows excellent anti-swelling property, low cell cytotoxicity, hemocompatibility, and inflammation response. In particular, the protein-peptide supramolecular biomaterials can in vivo dissociate and degrade within two weeks, which can well match with the time-window of the dural repairing. This work underscores the versatility and availability of the supramolecular toolbox in the easy-to-implement fabrication of protein-peptide biomaterials.

Management of metabolic syndrome by nutraceuticals prepared from chitosan and ferulic acid with or without beta-sitosterol and their nanoforms

Dyslipidemia, steatohepatitis and insulin resistance are among the components of metabolic syndrome (MS). Nutraceuticals containing chitosan, beta-sitosterol and/or ferulic acid and their nanostructures could have a potential role for management of MS. The aim of the present study was to assess the efficacy of the aforementioned nutraceuticals in treatment of MS in rat and their interaction with atorvastatin, a hypolipidemic drug. The two nutraceuticals and their nanostructures were prepared and the nanostructures were assessed by transmission electron microscope and Fourier-Transform Infra-red Spectrometry. MS was induced in rats by feeding high fructose-high fat diet (HFFD). Different groups of rats fed HFFD and treated with the different nutraceuticals, atorvastatin and atorvastatin in combination with different nutraceuticals, control fed on balanced diet and control consumed HFFD without treatments were run. Plasma glucose, lipid profile, aminotransferases activity, total antioxidant capacity, malondialdehyde, urea, creatinine, insulin, high sensitivity C-reactive protein, and adiponectin were assessed along with calculation of insulin resistance. Liver fat and histopathology were investigated. All nutraceuticals in original and nanostructures showed beneficial effects in the treatment of MS, superiority was ascribed to nutraceuticals composed of chitosan and ferulic acid in both forms. A more promising treatment of MS belonged to atorvastatin administered with the different nutraceuticals.

Determination of Common microRNA Biomarker Candidates in Stage IV Melanoma Patients and a Human Melanoma Cell Line: A Potential Anti-Melanoma Agent Screening Model

MicroRNAs (miRNAs) are small, non-coding RNAs that play an important role in regulating gene expression. Dysregulation of miRNA expression is commonly observed in cancer, and it can contribute to malignant cell growth. Melanoma is the most fatal type of skin malignant neoplasia. Some microRNAs can be prospective biomarkers for melanoma in stage IV (advanced) at higher risk of relapses and require validation for diagnostic purposes. This work aimed to (1) determine the most significant microRNA biomarker candidates in melanoma using content analysis of the scientific literature, (2) to show microRNA biomarker candidates' diagnostic efficacy between melanoma patients and healthy control groups in a small-scale preliminary study by blood plasma PCR analysis, (3) to determine significant microRNA markers of the MelCher human melanoma cell line, which are also detected in patients with melanoma, that can be used as markers of drug anti-melanoma activity, and (4) test anti-melanoma activity of humic substances and chitosan by their ability to reduce level of marker microRNAs. The content analysis of the scientific literature showed that hsa-miR-149-3p, hsa-miR-150-5p, hsa-miR-193a-3p, hsa-miR-21-5p, and hsa-miR-155-5p are promising microRNA biomarker candidates for diagnosing melanoma. Estimating microRNA in plasma samples showed that hsa-miR-150-5p and hsa-miR-155-5p may have a diagnostic value for melanoma in stage IV (advanced). When comparing ΔCt hsa-miR-150-5p and ΔCt hsa-miR-155-5p levels in melanoma patients and healthy donors, statistically significant differences were found (p = 0.001 and p = 0.001 respectively). Rates ΔCt were significantly higher among melanoma patients (medians concerning the reference gene miR-320a were 1.63 (1.435; 2.975) and 6.345 (4.45; 6.98), respectively). Therefore, they persist only in plasma from the melanoma patients group but not in the healthy donors group. In human wild-type stage IV melanoma (MelCher) cell culture, the presence of hsa-miR-150-5p and hsa-miR-155-5p in supernatant was detected. The ability of humic substance fractions and chitosan to reduce levels of hsa-miR-150-5p and hsa-miR-155-5p was tested on MelCher cultures, which is associated with anti-melanoma activity. It was found that the hymatomelanic acid (HMA) fraction and its subfraction UPLC-HMA statistically significantly reduced the expression of miR-150-5p and miR-155-5p (p ≤ 0.05). For the humic acid (HA) fraction, this activity was determined only to reduce miR-155-5p (p ≤ 0.05). Ability to reduce miR-150-5p and miR-155-5p expression on MelCher cultures was not determined for chitosan fractions with a molecular weight of 10 kDa, 120 kDa, or 500 kDa. Anti-melanoma activity was also determined in the MTT test on MelCher cultures for explored substances. The median toxic concentration (TC50) was determined for HA, HMA and UPLC-HMA (39.3, 39.7 and 52.0 μg/mL, respectively). For 10 kDa, 120 kDa, or 500 kDa chitosan fractions TC50 was much higher compared to humic substances (508.9, 6615.9, 11352.3 μg/mL, respectively). Thus, our pilot study identified significant microRNAs for testing the in vitro anti-melanoma activity of promising drugs and melanoma diagnostics in patients. Using human melanoma cell cultures gives opportunities to test new drugs on a culture that has a microRNA profile similar to that of patients with melanoma, unlike, for example, murine melanoma cell cultures. It is necessary to conduct further studies with a large number of volunteers, which will make it possible to correlate the profile of individual microRNAs with specific patient data, including the correlation of the microRNA profile with the stage of melanoma.

Transcriptome wide analyses reveal intraspecific diversity in thermal stress responses of a dominant habitat-forming species

The impact of climate change on biodiversity has stimulated the need to understand environmental stress responses, particularly for ecosystem engineers whose responses to climate affect large numbers of associated organisms. Distinct species differ substantially in their resilience to thermal stress but there are also within-species variations in thermal tolerance for which the molecular mechanisms underpinning such variation remain largely unclear. Intertidal mussels are well-known for their role as ecosystem engineers. First, we exposed two genetic lineages of the intertidal mussel Perna perna to heat stress treatments in air and water. Next, we ran a high throughput RNA sequencing experiment to identify differences in gene expression between the thermally resilient eastern lineage and the thermally sensitive western lineage. We highlight different thermal tolerances that concord with their distributional ranges. Critically, we also identified lineage-specific patterns of gene expression under heat stress and revealed intraspecific differences in the underlying transcriptional pathways in response to warmer temperatures that are potentially linked to the within-species differences in thermal tolerance. Beyond the species, we show how unravelling within-species variability in mechanistic responses to heat stress promotes a better understanding of global evolutionary trajectories of the species as a whole in response to changing climate.

Biopharmaceutical applications of microbial polysaccharides as materials: A review

Biological characteristics of natural polymers make microbial polysaccharides an excellent choice for biopharmaceuticals. Due to its easy purifying procedure and high production efficiency, it is capable of resolving the existing application issues associated with some plant and animal polysaccharides. Furthermore, microbial polysaccharides are recognized as prospective substitutes for these polysaccharides based on the search for eco-friendly chemicals. In this review, the microstructure and properties of microbial polysaccharides are utilized to highlight their characteristics and potential medical applications. From the standpoint of pathogenic processes, in-depth explanations are provided on the effects of microbial polysaccharides as active ingredients in the treatment of human diseases, anti-aging, and drug delivery. In addition, the scholarly developments and commercial applications of microbial polysaccharides as medical raw materials are also discussed. The conclusion is that understanding the use of microbial polysaccharides in biopharmaceuticals is essential for the future development of pharmacology and therapeutic medicine.

Synthesis, characterization, and anticancer activity of chitosan functionalized isatin based thiosemicarbazones, and their copper(II) complexes

The one-pot synthetic method of condensation of isatin and 5-chloroisatin on to amino group at C2 position of the pyranose ring chitosan in chitosan thiosemicarbazide was employed to get these chitosan thiosemicarbazones (TSCs). The partial incorporation of thiosemicarbazone moiety in chitosan was shown by FT-IR and ¹³C NMR spectroscopic studies, powder X ray diffraction, and CHNS microanalysis. The NOS tridentate coordination behavior of TSCs with copper(II) chloride to give the square planar complexes was established by FT-IR spectroscopic data, magnetic susceptibility measurement, and EPR spectral analysis. The thermal stability of these biomaterial chitosan derivatives till the commencement of chain disruption at 200C was shown by thermal studies. As revealed by colorimetric MTT assays, the in vitro anticancer activity enhancement accorded with the functionalization of chitosan as isatin based chitosan TSCs, and NOS tridentate coordination of TSCs plus a monodentate coordination of chloride ion with copper(II) ion. Only a marginal activity difference of these compounds was observed against the tumorigenic MDCK and MCF-7 cancer cell lines, irrespective of unit molecular weight (M_w) and degree of deacetylation (DDA) of ring chitosan. The 5-chloroisatin chitosan TSCs showed better activity than isatin chitosan TSCs against both the cell lines.

Chitosan nanocarriers containing essential oils as a green strategy to improve the functional properties of chitosan: A review

Large amounts of agricultural waste, especially marine product waste, are produced annually. These wastes can be used to produce compounds with high-added value. Chitosan is one such valuable product that can be obtained from crustacean wastes. Various biological activities of chitosan and its derivatives, especially antimicrobial, antioxidant, and anticancer properties, have been confirmed by many studies. The unique characteristics of chitosan, especially chitosan nanocarriers, have led to the expansion of using chitosan in various sectors, especially in biomedical sciences and food industries. On the other hand, essential oils, known as volatile and aromatic compounds of plants, have attracted the attention of researchers in recent years. Like chitosan, essential oils have various biological activities, including antimicrobial, antioxidant, and anticancer. In recent years, one of the ways to improve the biological properties of chitosan is to use essential oils encapsulated in chitosan nanocarriers. Among the various biological activities of chitosan nanocarriers containing essential oils, most studies conducted in recent years have been in the field of antimicrobial activity. It was documented that the antimicrobial activity was increased by reducing the size of chitosan particles in the nanoscale. In addition, the antimicrobial activity was intensified when essential oils were in the structure of chitosan nanoparticles. Essential oils can increase the antimicrobial activity of chitosan nanoparticles with synergistic effects. Using essential oils in the structure of chitosan nanocarriers can also improve the other biological properties (antioxidant and anticancer activities) of chitosan and increase the application fields of chitosan. Of course, using essential oils in chitosan nanocarriers for commercial use requires more studies, including stability during storage and effectiveness in real environments. This review aims to overview recent studies on the biological effects of essential oils encapsulated in chitosan nanocarriers, with notes on their biological mechanisms.

Nano-Sized Fucoidan Interpolyelectrolyte Complexes: Recent Advances in Design and Prospects for Biomedical Applications

The marine polysaccharide fucoidan (FUC) is a promising polymer for pharmaceutical research and development of novel drug delivery systems with modified release and targeted delivery. The presence of a sulfate group in the polysaccharide makes FUC an excellent candidate for the formation of interpolyelectrolyte complexes (PECs) with various polycations. However, due to the structural diversity of FUC, the design of FUC-based nanoformulations is challenging. This review describes the main strategies for the use of FUC-based PECs to develop drug delivery systems with improved biopharmaceutical properties, including nanocarriers in the form of FUC-chitosan PECs for pH-sensitive oral delivery, targeted delivery systems, and polymeric nanoparticles for improved hydrophobic drug delivery (e.g., FUC-zein PECs, core-shell structures obtained by the layer-by-layer self-assembly method, and self-assembled hydrophobically modified FUC particles). The importance of a complex study of the FUC structure, and the formation process of PECs based on it for obtaining reproducible polymeric nanoformulations with the desired properties, is also discussed.

Thiolated pectin-chitosan composites: Potential mucoadhesive drug delivery system with selective cytotoxicity towards colorectal cancer

Mucoadhesive drug delivery systems (DDS) may promote safer chemotherapy for colorectal cancer (CRC) by maximizing local drug distribution and residence time. Carbohydrate polymers, e.g. pectin (P) and chitosan (CS), are potential biomaterials for CRC-targeted DDS due to their gelling ability, mucoadhesive property, colonic digestibility, and anticancer activity. Polymer mucoadhesion is augmentable by thiolation, e.g. pectin to thiolated pectin (TP). Meanwhile, P-CS polyelectrolyte complex has been shown to improve structural stability. Herein, we fabricated, characterized, and evaluated 5-fluorouracil-loaded primary DDS combining TP and CS as a composite (TPCF) through triple crosslinking actions (calcium pectinate, polyelectrolyte complex, disulfide). Combination of these crosslinking yields superior mucoadhesion property relative to single- or dual-crosslinked counterparts, with comparable drug release profile and drug compatibility. PCF and TPCF exhibited targeted cytotoxicity towards HT29 CRC cells with milder cytotoxicity towards HEK293 normal cells. In conclusion, TP-CS composites are promising next-generation mucoadhesive and selectively cytotoxic biomaterials for CRC-targeted DDS.

Biocomposite Materials Based on Poly(3-hydroxybutyrate) and Chitosan: A Review

One of the important directions in the development of modern medical devices is the search and creation of new materials, both synthetic and natural, which can be more effective in their properties than previously used materials. Traditional materials such as metals, ceramics, and synthetic polymers used in medicine have certain drawbacks, such as insufficient biocompatibility and the emergence of an immune response from the body. Natural biopolymers have found applications in various fields of biology and medicine because they demonstrate a wide range of biological activity, biodegradability, and accessibility. This review first described the properties of the two most promising biopolymers belonging to the classes of polyhydroxyalkanoates and polysaccharides-polyhydroxybutyrate and chitosan. However, homopolymers also have some disadvantages, overcome which becomes possible by creating polymer composites. The article presents the existing methods of creating a composite of two polymers: copolymerization, electrospinning, and different ways of mixing, with a description of the properties of the resulting compositions. The development of polymer composites is a promising field of material sciences, which allows, based on the combination of existing substances, to develop of materials with significantly improved properties or to modify of the properties of each of their constituent components.

Giant Viruses as a Source of Novel Enzymes for Biotechnological Application

The global demand for industrial enzymes has been increasing in recent years, and the search for new sources of these biological products is intense, especially in microorganisms. Most known viruses have limited genetic machinery and, thus, have been overlooked by the enzyme industry for years. However, a peculiar group of viruses breaks this paradigm. Giant viruses of the phylum Nucleocytoviricota infect protists (i.e., algae and amoebae) and have complex genomes, reaching up to 2.7 Mb in length and encoding hundreds of genes. Different giant viruses have robust metabolic machinery, especially those in the Phycodnaviridae and Mimiviridae families. In this review, we present some peculiarities of giant viruses that infect protists and discuss why they should be seen as an outstanding source of new enzymes. We revisited the genomes of representatives of different groups of giant viruses and put together information about their enzymatic machinery, highlighting several genes to be explored in biotechnology involved in carbohydrate metabolism, DNA replication, and RNA processing, among others. Finally, we present additional evidence based on structural biology using chitinase as a model to reinforce the role of giant viruses as a source of novel enzymes for biotechnological application.

Comparative Efficiency of Gene-Activated Matrices Based on Chitosan Hydrogel and PRP Impregnated with BMP2 Polyplexes for Bone Regeneration

Gene therapy is one of the most promising approaches in regenerative medicine. Gene-activated matrices provide stable gene expression and the production of osteogenic proteins in situ to stimulate osteogenesis and bone repair. In this study, we developed new gene-activated matrices based on polylactide granules (PLA) impregnated with BMP2 polyplexes and included in chitosan hydrogel or PRP-based fibrin hydrogel. The matrices showed high biocompatibility both in vitro with mesenchymal stem cells and in vivo when implanted intramuscularly in rats. The use of porous PLA granules allowed the inclusion of a high concentration of polyplexes, and the introduction of the granules into hydrogel provided the gradual release of the plasmid constructs. All gene-activated matrices showed transfecting ability and ensured long-term gene expression and the production of target proteins in vitro. At the same time, the achieved concentration of BMP-2 was sufficient to induce osteogenic differentiation of MSCs. When implanted into critical-size calvarial defects in rats, all matrices with BMP2 polyplexes led to new bone formation. The most significant effect on osteoinduction was observed for the PLA/PRP matrices. Thus, the developed gene-activated matrices were shown to be safe and effective osteoplastic materials. PLA granules and PRP-based fibrin hydrogel containing BMP2 polyplexes were shown to be the most promising for future applications in bone regeneration.

Fabrication and analysis of chitosan oligosaccharide based mucoadhesive patch for oromucosal drug delivery

OBJECTIVE

Fabrication and analyses of mucoadhesive patches made from chitosan oligosaccharide for the purpose of oromucosal drug delivery.

SIGNIFICANCE

The mucosal epithelium in the oral cavity, consisting of buccal and sublingual epithelium, has gained significant attention in the last decade as an alternative anatomical site for systemic drug delivery that could potentially minimize the challenges of solid oral dosage and parenteral delivery. In this study, we have fabricated and tested drug-loaded chitosan oligosaccharide-based patches for the oromucosal drug delivery.

METHODS

The chitosan oligosaccharide (with and without alginate) based patches were fabricated using the conventional solvent casting method and were analyzed for their swelling capacity, hydrophilicity, anti-cancer activity, in vitro drug release, and in vivo drug release activity. The in-house developed artificial saliva was used for the swelling study.

RESULTS

Alginate-containing patches showed lesser swelling ability compared to the bare chitosan oligosaccharide-based patches. The former was also found to be more hydrophobic compared to the latter one. Both the unloaded patches restricted the growth of epithelial cancer cells indicating their anti-cancer behavior. In vitro drug release indicated a super case II release pattern while in vivo study demonstrated the release of drug from the patch into the plasma indicating the purpose of the fabricated patch.

CONCLUSIONS

The chitosan oligosaccharide-based mucoadhesive hydrogel patch fabricated in this study can be highly suitable for possible translational purposes.

Characterization and Optimization of Chitosan Production by Aspergillus terreus

The production of the amino polysaccharide (chitosan) from crustacean sources has faced many hindrances due to environmental, seasonal and noneconomic issues. On the other hand, mycogenic chitosan has many advantages that make it suitable for many medical and nutritional applications over the non-mycological counterparts. A number of fungal isolates have been screened for chitosan production, where the most potent fungal isolate has been genetically identified using 18S rDNA and selected to be the focus of the current study. The factors affecting chitosan production by the selected fungal isolate have been studied and numerically optimized and validated using Box–Behnken design. The produced chitosan has been collected, purified and characterized for the degree of deacetylation (DDA), molecular weight (MW), water-binding (WBC) and fat-binding capacities (FBC). Results showed that Aspergillus terreus (F3) was the most potent chitosan-producing fungal isolate with maximum validated productivity (2.92 g/l) at the following conditions: glucose, 35.6 g/l; (NH4)2SO4, 4.6 g/l; CaCl2, 0.29 g/l; and pH 7.9 at 23.2 °C for 10 days. The purified chitosan has the following characteristics: 71.9%, DDA; 54.1165 KD, MW; 58.6%, WBC; and 47.6%, FBC. The features and applications of fungal chitosan are not fully uncovered which necessitates further studies.

Effect of chitooligosaccharides with a specific degree of polymerization on multiple targets in T2DM mice

Chitooligosaccharides (COS) are found naturally in the ocean and present a variety of physiological activities, of which hypoglycemic action has attracted considerable research attention. This study aimed to assess the therapeutic effect of COS on mice suffering from type 2 diabetes mellitus (T2DM). COS effectively reduced blood glucose and blood lipid levels and improved glucose tolerance. Furthermore, COS revealed strong inhibitory activity against α-glucosidase, reducing postprandial blood glucose levels. Molecular docking data showed that COS might interact with surrounding amino acids to form a complex and decrease α-glucosidase activity. Additionally, COS enhanced insulin signal transduction and glycogen synthesis while restricting gluconeogenesis in the liver and muscles, reducing insulin resistance (IR) as a result. Moreover, COS effectively protected and restored islet cell function to increase insulin secretion. These results indicated that COS exhibited a significant hypoglycemic effect with multi-target participation. Therefore, COS may serve as a new preventive or therapeutic drug for diabetes to alleviate metabolic syndrome.

Biomaterial-Based Therapeutic Strategies for Obesity and Its Comorbidities

Obesity is a global public health issue that results in many health complications or comorbidities, including type 2 diabetes mellitus, cardiovascular disease, and fatty liver. Pharmacotherapy alone or combined with either lifestyle alteration or surgery represents the main modality to combat obesity and its complications. However, most anti-obesity drugs are limited by their bioavailability, target specificity, and potential toxic effects. Only a handful of drugs, including orlistat, liraglutide, and semaglutide, are currently approved for clinical obesity treatment. Thus, there is an urgent need for alternative treatment strategies. Based on the new revelation of the pathogenesis of obesity and the efforts toward the multi-disciplinary integration of materials, chemistry, biotechnology, and pharmacy, some emerging obesity treatment strategies are gradually entering the field of preclinical and clinical research. Herein, by analyzing the current situation and challenges of various new obesity treatment strategies such as small-molecule drugs, natural drugs, and biotechnology drugs, the advanced functions and prospects of biomaterials in obesity-targeted delivery, as well as their biological activities and applications in obesity treatment, are systematically summarized. Finally, based on the systematic analysis of biomaterial-based obesity therapeutic strategies, the future prospects and challenges in this field are proposed.

Dual Role of Chitin as the Double Edged Sword in Controlling the NLRP3 Inflammasome Driven Gastrointestinal and Gynaecological Tumours

The role of NLRP3 in the tumour microenvironment is elusive. In some cancers, the activation of NLRP3 causes a worse prognosis and in some cancers, NLRP3 increases chances of survivability. However, in many cases where NLRP3 has a protumorigenic role, inhibition of NLRP3 would be a crucial step in therapy. Consequently, activation of NLRP3 would be of essence when inflammation is required. Although many ways of inhibiting and activating NLRP3 in cancers have been discussed before, not a lot of focus has been given to chitin and chitosan in this context. The availability of these marine compounds and their versatility in dealing with inflammation needs to be investigated further in relation with cancers, along with other natural extracts. In this review, the effects of NLRP3 on gastrointestinal and gynaecological cancers and the impact of different natural extracts on NLRP3s with special emphasis on chitin and chitosan is discussed. A research gap in using chitin derivatives as anti/pro-inflammatory agents in cancer treatment has been highlighted.

Molecular modifications, biological activities, and applications of chitosan and derivatives: A recent update

Polysaccharides arouse great interest due to their structure and unique properties, such as biocompatibility, biodegradability, and absence of toxicity. Polysaccharides from marine sources are particularly useful due to the wide variety of applications and biological activities. Chitosan, a deacetylated derivative of chitin, is an example of an interesting bioactive marine-derived polysaccharide. Moreover, a wide variety of chemical modifications and conjugation of chitosan with other bioactive molecules are responsible for improvements in physicochemical properties and biological activities, expanding the range of applications. An overview of the synthetic approaches for preparing chitosan, chitosan derivatives, and conjugates is described and discussed. A recent update of the biological activities and applications in different research fields, mainly focused on the last 5 years, is presented, highlighting current trends.

Multiple Roles of Chitosan in Mucosal Drug Delivery: An Updated Review

Chitosan (CS) is a linear polysaccharide obtained by the deacetylation of chitin, which, after cellulose, is the second biopolymer most abundant in nature, being the primary component of the exoskeleton of crustaceans and insects. Since joining the pharmaceutical field, in the early 1990s, CS attracted great interest, which has constantly increased over the years, due to its several beneficial and favorable features, including large availability, biocompatibility, biodegradability, non-toxicity, simplicity of chemical modifications, mucoadhesion and permeation enhancer power, joined to its capability of forming films, hydrogels and micro- and nanoparticles. Moreover, its cationic character, which renders it unique among biodegradable polymers, is responsible for the ability of CS to strongly interact with different types of molecules and for its intrinsic antimicrobial, anti-inflammatory and hemostatic activities. However, its pH-dependent solubility and susceptibility to ions presence may represent serious drawbacks and require suitable strategies to be overcome. Presently, CS and its derivatives are widely investigated for a great variety of pharmaceutical applications, particularly in drug delivery. Among the alternative routes to overcome the problems related to the classic oral drug administration, the mucosal route is becoming the favorite non-invasive delivery pathway. This review aims to provide an updated overview of the applications of CS and its derivatives in novel formulations intended for different methods of mucosal drug delivery.

Nanoencapsulation of Gla-Rich Protein (GRP) as a Novel Approach to Target Inflammation

Chronic inflammation is a major driver of chronic inflammatory diseases (CIDs), with a tremendous impact worldwide. Besides its function as a pathological calcification inhibitor, vitamin K-dependent protein Gla-rich protein (GRP) was shown to act as an anti-inflammatory agent independently of its gamma-carboxylation status. Although GRP’s therapeutic potential has been highlighted, its low solubility at physiological pH still constitutes a major challenge for its biomedical application. In this work, we produced fluorescein-labeled chitosan-tripolyphosphate nanoparticles containing non-carboxylated GRP (ucGRP) (FCNG) via ionotropic gelation, increasing its bioavailability, stability, and anti-inflammatory potential. The results indicate the nanosized nature of FCNG with PDI and a zeta potential suitable for biomedical applications. FCNG’s anti-inflammatory activity was studied in macrophage-differentiated THP1 cells, and in primary vascular smooth muscle cells and chondrocytes, inflamed with LPS, TNFα and IL-1β, respectively. In all these in vitro human cell systems, FCNG treatments resulted in increased intra and extracellular GRP levels, and decreased pro-inflammatory responses of target cells, by decreasing pro-inflammatory cytokines and inflammation mediators. These results suggest the retained anti-inflammatory bioactivity of ucGRP in FCNG, strengthening the potential use of ucGRP as an anti-inflammatory agent with a wide spectrum of application, and opening up perspectives for its therapeutic application in CIDs.

Chitosan: A review of molecular structure, bioactivities and interactions with the human body and micro-organisms

Chitosan has many desirable attributes e.g. antimicrobial properties and promoting wound healing, and is used in various applications. This article first discusses how degree of deacetylation (DD) and molecular weight (MW) impacts on what level of bioactivities chitosan manifests, then introduces the "molecular chain configuration" model to explain various possible mechanisms of antimicrobial interactions between chitosan with different MW and different types of bacteria. Similarly, the possible pathways of how chitosan reacts with cancer and the body's immune system to demonstrate immune and antitumor effects are also discussed by using this model. Moreover, the possible mechanisms of how chitosan enhances coagulation and wound healing are also discussed. With these beneficial bioactivities in mind, the application of chitosan in surgery, tissue engineering and oncology is outlined. This review concludes that as chitosan demonstrates many beneficial bioactivities via multiple mechanisms, it is an important polymer with a promising future in medicine.

Bone Quantification Around Chitosan-Coated Titanium Dental Implants: A Preliminary Study by Micro-CT Analysis in Jaw of a Canine Model

Surface treatments of Ti in the dental implant industry are performed with the aim of in-creasing its bioactivity and osseointegration capacity. Chitosan (Cht) is a polysaccharide that has been proposed as a promising biomaterial in tissue engineering and bone regeneration, due to its ability to stimulate the recruitment and adhesion of osteogenic progenitor cells. The aim of our preliminary study was to evaluate, by micro-computed tomography (micro-CT), the osseointegration and bone formation around Cht-coated implants and to compare them with conventional surface-etched implants (SLA type). Four im-plants (8.5 mm length × 3.5 mm Ø) per hemiarch, were inserted into the jaws of five dogs, divided into two groups: chitosan-coated implant group (ChtG) and control group (CG). Twelve weeks after surgery, euthanasia was performed, and sectioned bone blocks were obtained and scanned by micro-CT and two bone parameters were measured: bone in contact with the implant surface (BCIS) and peri-implant bone area (PIBA). For BCIS and PIBA statistically significant values were obtained for the ChtG group with respect to CG (p = 0.005; p = 0.014 and p < 0.001 and p = 0.002, respectively). The results, despite the limitations, demonstrated the usefulness of chitosan coatings. However, studies with larger sample sizes and adequate experimental models would be necessary to confirm the results.

Characterization of a β-N-acetylhexosaminidase with transglycosylation activity from Metarhizium sp. A34

In applications of chitin, one of the most abundant resources on earth, human milk oligosaccharides with many health functions were synthesized by transglycosylation of β-N-acetylhexosaminidase. Synthesis of new transfer products can be expected by other β-N-acetylhexosaminidases in nature. A total of 38 microorganisms that secrete β-N-acetylhexosaminidases with transglycosylation activity were isolated from a soil screen. Using N,N'-diacetylchitobiose as the substrate, the transfer ratio increased with a decrease in substrate degradation when it was less than 60%. Metarhizium sp. A34 β-N-acetylhexosaminidase had high transglycosylation activity and showed a maximum production of the oligosaccharides against the substrate degradation where (GlcNAc)₅ and (GlcNAc)₄ were produced in addition to (GlcNAc)₃ . The maximum curve was attributed to a sequential reaction of transglycosylation followed by hydrolysis where oligosaccharides are an intermediate product and are hydrolyzed in a second step. The purified β-N-acetylhexosaminidase from Metarhizium sp. A34 had an optimal pH of 5 and was stable from pH 7 to 8. At pH 5, it had an optimal temperature of 40°C and was stable up to 30°C for 30 min. This enzyme had high thermostability up to 55°C when bound to the cell wall. The acceptor specificity for the transglycosylation reaction was enhanced for lower molecular weight sugar alcohols in the order of glycerin (C3), erythritol (C4), and xylitol (C5). The transfer product with glycerin was identified as 1-O-β-d-N-acetylglucosaminyl glycerin, which may prove useful as a starting material for new glycolipids in food applications. PRACTICAL APPLICATION: Metarhizium sp. A34 β-N-acetylhexosaminidase produced 1-O-β-d-N-acetylglucosaminyl glycerin through the transglycosylation. Chitin oligosaccharides of the donor are obtained by hydrolysis of chitin. 1-O-β-d-N-Acetylglucosaminyl glycerin may be useful to start material for the synthesis of new glycolipids. High thermostability of this enzyme is useful to prevention of contamination in the transglycosylation reaction.