Chitooligosaccharides for wound healing biomaterials engineering

Chitosan-gallic acid conjugate edible coating film for perishable fruits

Approximately 30 % of global agricultural land is used to produce food that is ultimately lost or wasted, making it imperative to explore strategies for mitigating this waste. This study explored the potential of chitosan (CS) derivatives as edible coatings to extend food shelf life. Although soluble CS derivatives such as glycol CS are suitable coatings, their antimicrobial properties often diminish with increased solubility. To address this issue, gallic acid (GA), a polyphenol, was conjugated with CS using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide/N-hydroxysuccinimide (EDC/NHS) chemistry to create edible coating solutions. The resulting CS-GA films exhibited remarkable solubility, mechanical strength, UV-blocking properties, and superior antioxidant and antimicrobial properties. Furthermore, these films exhibited a high affinity for hydrophobic fruit surfaces while also facilitating easy washing, making them an alternative for consumers who are averse to film-coated products. The CS-GA-coated fruits exhibited minimal surface spoilage, decreased mass loss, and increased firmness. Therefore, these CS-GA conjugate coatings hold significant potential as eco-friendly, edible, and washable food packaging coatings.

Chitooligosaccharide-modified PLGA-loaded PPD nanoparticles ameliorated sepsis-associated acute kidney injury via the NF-κB signaling pathway

OBJECTIVES

Sepsis-associated acute kidney injury (SA-AKI) is a significant clinical challenge with high morbidity and mortality. Low bioavailability of protopanaxadiol (PPD) limits its clinical application. In this study, PPD was encapsulated with chitooligosaccharide (COS) modified polylactic-co-glycolic acid (PLGA) to develop novel nanomedicines for the treatment of SA-AKI.

METHODS

COS-PLGA-PPD nanoparticles were prepared by emulsified solvent evaporation method, and their properties were evaluated. In vitro, the anti-inflammatory and protective effects of COS-PLGA-PPD NPs were investigated in a cellular model of LPS-induced NRK-52E cells and their uptake in Caco-2 cells. Indicators of renal injury, inflammation, and NF-κB signaling pathway were evaluated by injecting LPS into SD rats and inducing SA-AKI model in vivo. The oral bioavailability of nanoparticles was evaluated by pharmacokinetics.

RESULTS

Compared with PPD and unmodified nanoparticles, COS-PLGA-PPD NPs were more stable, with a particle size of 139.69 nm, which enhanced the viability of NRK-52E cells, increased the uptake of Caco-2 cells, alleviated the symptoms of SA-AKI in rats, inhibited the NF-κB signaling pathway, reduced the expression of inflammatory factors, and had a bioavailability 1.7-fold that of PPD.

CONCLUSION

COS-PLGA-PPD NPs ameliorate LPS-induced SA-AKI in rats by inhibiting the NF-κB signaling pathway, providing a basis for the treatment of SA-AKI.

The preparation, modification and hepatoprotective activity of chitooligosaccharides: A review

Chitooligosaccharides (COS) has attracted increasing attention due to the various promising bioactivities, tremendous potential in agricultural, environmental nutritional and functional food fields. COS as the major degradation product from chitosan or chitin is prepared via enzymatic, chemical and physical methods. Further obtained COS generally possesses different structural characteristics, such as molecular weight, degree of acetylation and degree of polymerization. Innovations into COS modification has also broadened application of COS in nutrition as well as in agricultural safety. Due to the affinity between structure and bioactivity, diversity of structural characteristics endows COS with various bioactivities like antitumor, antioxidant and anti-inflammatory effects, especially hepatoprotective activity. Therefore, the present review narrates the recent developments in COS physicochemical properties, while paying considerable attention to preparation strategies of COS and their advantages and disadvantages. Moreover, the modification of COS is also discussed including alkylation, quaternization and sulfation, herein the structure-activity relationship of COS was highlighted. Additionally, we summarize the latest research on hepatoprotective activity and mechanisms of COS. Eventually, the future directions of research on COS were discussed, which would provide a new appreciation for the future use of COS.

Mesenchymal stem cell-derived exosomes for management of prostate cancer: An updated view

Prostate cancer represents the second most prevalent form of cancer found in males, and stands as the fifth primary contributor to cancer-induced mortality on a global scale. Research has shown that transplanted mesenchymal stem cells (MSCs) can migrate by homing to tumor sites in the body. In prostate cancer, researchers have explored the fact that MSC-based therapies (including genetically modified delivery vehicles or vectors) and MSC-derived exosomes are emerging as attractive options to improve the efficacy and safety of traditional cancer therapies. In addition, researchers have reported new insights into the application of extracellular vesicle (EV)-MSC therapy as a novel treatment option that could provide a more effective and targeted approach to prostate cancer treatment. Moreover, the new generation of exosomes, which contain biologically functional molecules as signal transducers between cells, can simultaneously deliver different therapeutic agents and induce an anti-tumor phenotype in immune cells and their recruitment to the tumor site. The results of the current research on the use of MSCs in the treatment of prostate cancer may be helpful to researchers and clinicians working in this field. Nevertheless, it is crucial to emphasize that although dual-role MSCs show promise as a therapeutic modality for managing prostate cancer, further investigation is imperative to comprehensively grasp their safety and effectiveness. Ongoing clinical trials are being conducted to assess the viability of MSCs in the management of prostate cancer. The results of these trials will help determine the viability of this approach. Based on the current literature, engineered MSCs-EV offer great potential for application in targeted tumor therapy.

Chitosan-Based Biomaterial in Wound Healing: A Review

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

Research progress on chitin/chitosan-based emulsion delivery systems and their application in lipid digestion regulation

Excessive lipid intake is linked to an elevated risk of health problems. However, reducing lipid contents may influence food structure and flavor. Some alternatives are needed to control the lipid absorption. Emulsions are common carriers for lipids, which can control the hydrolysis and absorption of lipids. Chitin (Ch) and chitosan (CS) are natural polysaccharides with good biodegradability, biocompatibility, and unique cationic properties. They have been reported to be able to delay lipolysis, which can be regarded as one of the most promising agents that regulates lipid digestion (LiD). The application of Ch/CS and their derivatives in emulsions are summarized in this review with a focus on their performances and mechanisms for LiD regulation, aiming to provide theoretical guidance for the development of novel Ch/CS emulsions, and the regulation of LiD. A reasonable design of emulsion interface can provide its resistance to the external environment and then control LiD. The properties of emulsion interface are the key factors affecting LiD. Therefore, systematic study on the relationship between Ch/CS-based emulsion structure and LiD can not only instruct the reasonable design of emulsion interface to accurately regulate LiD, but also provide scientific guidelines for applying Ch/CS in functional food, medicine and other fields.

Helicity degree of carrageenan conformation determines the polysaccharide and water interactions

The polysaccharide in solution at critical concentration, Cc (g/L), is assimilated to a nano hydrogel (nHG) made of a single polysaccharide chain. Taking as reference the characteristic temperature of 20 ± 2 °C at which kappa-carrageenan (κ-Car) nHG swelling is greater with a Cc = 0.55 ± 0.05 g/L, the temperature of the minimum deswelling in the presence of KCl was found at 30 ± 2 °C for 5 mM with a Cc = 1.15 ± 0.05 g/L but not measurable above 100 °C for 10 mM of which Cc = 1.3 ± 0.05 g/L. Lowering the temperature to 5 °C, contraction of the nHG and further coil-helix transition with self-assembly increases the sample's viscosity, which steadily evolves with time in a logarithmic scale. Accordingly, the relative increment of the viscosity per unit of concentration, R_v (L/g), should increase in agreement with increasing polysaccharide concentration. But the R_v decreases for κ-Car samples above 3.5 ± 0.5 g/L in the presence of 10 mM KCl under steady shear 15 s^-1. This reflects a decrease of κ-Car helicity degree knowing that the polysaccharide is rather hydrophilic when its helicity degree is the lowest.

Phytochemical-Mediated Biosynthesis of Silver Nanoparticles from Strobilanthes glutinosus: Exploring Biological Applications

The application of green synthesis for silver nanoparticles in nanomedicine has experienced significant growth. Strobilanthes glutinosus, a plant primarily located in the Himalayas, remains largely unexplored. Considering the biomedical value of S. glutinosus, phytochemicals from this plant were used for the biosynthesis of silver nanoparticles. Silver nanoparticles were synthesized from aqueous extract of root and leaves of Strobilanthes glutinosus. The synthesized silver nanoparticles were characterized using UV-Vis spectrophotometry, Fourier-transform infrared spectroscopy, transmission electron microscopy, and X-ray diffraction. Total phenolic and flavonoid contents of plants were determined and compared with nanoparticles. The biomedical efficacy of plant extracts and silver nanoparticles was assessed using antioxidant and antibacterial assays. The UV-Vis spectra of leaf- and root-extract-mediated AgNPs showed characteristic peaks at 428 nm and 429 nm, respectively. TEM images revealed the polycrystalline and spherical shapes of leaf- and root-extract-mediated AgNPs with size ranges of 15-60 nm and 20-52 nm, respectively. FTIR findings shown the involvement of phytochemicals of root and leaf extracts in the reduction of silver ions into silver nanoparticles. The crystalline face-centered cubic structure of nanoparticles is depicted by the XRD spectra of leaf and root AgNPs. The plant has an ample amount of total phenolic content (TPC) and total flavonoid content (TFC), which enhance the scavenging activity of plant samples and their respective AgNPs. Leaf and root AgNPs have also shown good antibacterial activity, which may enhance the medicinal value of AgNPs.

Enhancing Enzyme Activity and Thermostability of Bacillus amyloliquefaciens Chitosanase BaCsn46A Through Saturation Mutagenesis at Ser196

Chitosanase plays an important role in chitooligosaccharides (COS) production. We found that the chitosanase (BaCsn46A) of Bacillus amyloliquefacien was a good candidate for chitosan hydrolysis of COS. In order to further improve the enzyme properties of BaCsn46A, the S196 located near the active center was found to be a critical site impacts on enzyme properties by sequence alignment analysis. Herein, saturation mutation was carried out to study role of 196 site on BaCsn46A catalytic function. Compared with WT, the specific enzyme activity of S196A increased by 118.79%, and the thermostability of S196A was much higher than WT. In addition, we found that the enzyme activity of S196P was 2.41% of that of WT, indicating that the type of amino acid in 196 site could significant affect the catalytic activity and thermostability of BaCsn46A. After molecular docking analysis we found that the increase in hydrogen bonds and decrease in unfavorable bonds interacting with the substrate were the main reason for the change of enzyme properties which is valuable for future studies on Bacillus species chitosanase.

Bibliometric analysis of the use of calcium alginate for wound dressing applications: A review

Wounds can cause many disorders and affect the quality of health, so it is necessary to develop wound dressings that have a role in accelerating the healing process. Wound dressings have evolved over time, and today there are many types of wound dressings that can suit the type of wound the patient has. This review discusses the development, types, and research directions of wound dressings from calcium alginate (CaAlg), using bibliometric analysis with time intervals from 1982 to 2021. It was found that, in the late 1990s, research related to this matter began to increase. United Kingdom, United States, China, Japan, and Italy are the five most influential countries. And from the results of the keyword analysis, it was found that, in addition to studying the general properties of wound dressings, currently there are many developments related to the structure of the material as well as the effect of adding drugs to wound dressings, so that the current study also displays various characterizations.

Nanoparticles Based on Chondroitin Sulfate from Tuna Heads and Chitooligosaccharides for Enhanced Water Solubility and Sustained Release of Curcumin

This study aimed to separate chondroitin sulfate (CS) from the heads of skipjack tuna (Katsuwonus pelamis) and yellowfin tuna (Thunnus albacares), by-products derived from canned tuna processing, via a biological process. The use of 1% w/w papain and an incubation time of 48 h resulted in a degree of hydrolysis of 93.75 ± 2.94% and a CS content of 59.53 ± 1.77 mg/100 g. The FTIR spectra of extracted CS products exhibited identical functional groups found in commercially available CS. The molecular weights of CS extracted from skipjack and yellowfin tuna heads were 11.0 kDa and 7.7 kDa, respectively. Subsequently, a CH:CS ratio of 3:2 for CS and chitooligosaccharides (CH) was chosen as the optimal ratio for the preparation of spherical nanoparticles, with %EE, mean particle size, PDI, and zeta potential values of 50.89 ± 0.66%, 128.90 ± 3.29 nm, 0.27 ± 0.04, and -12.47 ± 2.06, respectively. The CU content was enhanced to 127.21 ± 1.66 μg/mL. The release of CU from this particular nanosystem involved mainly a drug diffusion mechanism, with a burst release in the first 3 h followed by a sustained release of CU over 24 h. The DPPH and ABTS scavenging activity results confirmed the efficient encapsulation of CU into CHCS nanoparticles. This study will provide a theoretical basis for CS derived from tuna head cartilages to be used as a functional component with specific functional properties in food and biomedical applications.

Exploring Saduria entomon (Crustacea Isopoda) as a New Source for Chitin and Chitosan Isolation

Chitin and chitosan demand is growing very fast due to interest from industries such as pharmaceutical, cosmetic, agricultural and others. New sources for chitin and chitosan isolation are being extensively searched to fulfil this demand. In this paper, Saduria entomon a Baltic benthic crustacean, is evaluated as a source for chitin and chitosan isolation. Chitin and chitosan yield from S. entomon were 14.8 and 8.2%, respectively, in a similar range to other sources. Samples were characterized in terms of physicochemical properties (acetylation degree, molecular weight, thermal stability, and crystallinity) and two biological properties, antimicrobial activity and antioxidant activity were evaluated. Chitosan S. entomon exhibited antimicrobial activity against S. aureus but not against E. coli. An antioxidant activity of 20.98 TROLOX µmol equivalent/g polymer was detected for the chitosan sample. These properties are very promising for the use of this organism as a source for chitin and chitosan isolation in the biomedical field.

Chitosan degradation products promote healing of burn wounds of rat skin

Burns can impair the barrier function of the skin, and small burns can also cause high mortality. The WHO has described that over 180,000 people die of burns worldwide each year. Thus, the treatment of burn wounds is a major clinical challenge. Chitooligosaccharides (COS) are alkaline amino oligosaccharides with small molecular weights obtained by enzyme or chemical degradation of chitosan. With the characteristics of biocompatibility, water solubility and degradability, it has attracted increasing attention in the fields of biomedicine. In the present study, we used COS to treat deep second-degree burn wounds of rat skin and found that COS was able to promote wound healing. We also revealed that COS could promote fibroblast proliferation. Transcriptome sequencing analysis was performed on COS-treated fibroblasts to identify the underlying mechanisms. The results showed that COS was able to promote wound healing through regulation of the mitogen-activated protein kinase (MAPK) pathway and growth factor Hepatocyte Growth Factor (HGF). Our results provide a potential drug for burn wound therapy and the related molecular mechanism.

Multifunctional dual cross-linked poly (vinyl alcohol)/methacrylate hyaluronic acid/chitooligosaccharide-sinapic acid wound dressing hydrogel

Wound dressing hydrogel with multifunctional properties, including antioxidant and antimicrobial properties and appropriate mechanical, biological, and physical properties is of great interest in wound healing application and it is still a challenge. In the present study, chitooligosaccharides (COS)/ sinapic acid (SA) conjugate (COS-SA) was synthesized using H₂O₂-induced grafting polymerization, and photo cross-linkable hyaluronic acid was synthesized using methacrilation (HAMA). The synthesis of COS-SA and HAMA was confirmed by Fourier-transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, ultraviolet spectroscopy, and polyphenol assay. Subsequently, we developed duel cross-linked polyvinyl alcohol (PVA)/HAMA composite hydrogel encapsulated with COS-SA as an antioxidant and antimicrobial dressing for full-thickness wound healing application. The chemical, physical, mechanical, antioxidant, antimicrobial, in vitro biocompatibility, and in vivo wound healing properties of hydrogels were subsequently investigated. The results showed that the fabricated composite hydrogel had a uniform porous architecture, excellent fluid absorbability, and appropriate mechanical stability. The introduction of COSs-SA conjugate remarkably enhanced the in vitro biocompatibility, antioxidant, and antimicrobial properties of the hydrogel, leading to the significant promotion of in vivo full-thickness wound closure, re-epithelization, granulation tissue formation, and collagen deposition indicating that COSs-SA incorporated PVA/HAMA hydrogel wound dressing has significant potential for chronic wound healing application.

Potential Medical Applications of Chitooligosaccharides

Chitooligosaccharides, also known as chitosan oligomers or chitooligomers, are made up of chitosan with a degree of polymerization (DP) that is less than 20 and an average molecular weight (MW) that is lower than 3.9 kDa. COS can be produced through enzymatic conversions using chitinases, physical and chemical applications, or a combination of these strategies. COS is of significant interest for pharmacological and medical applications due to its increased water solubility and non-toxicity, with a wide range of bioactivities, including antibacterial, anti-inflammatory, anti-obesity, neuroprotective, anticancer, and antioxidant effects. This review aims to outline the recent advances and potential applications of COS in various diseases and conditions based on the available literature, mainly from preclinical research. The prospects of further in vivo studies and translational research on COS in the medical field are highlighted.

Chitin and Chitosan: Prospective Biomedical Applications in Drug Delivery, Cancer Treatment, and Wound Healing

Chitin and its derivative chitosan are highly abundant polymers in nature, appearing in both the shells and exoskeletons of various marine and non-marine species. Since they possess favorable properties, such as biocompatibility, biodegradability, non-toxicity, and non-immunogenicity, they have gained recent attention due to their enormous potential biomedical applications. The polycationic surface of chitosan enables it to form hydrogenic and ionic bonds with drug molecules, which is one of its most useful properties. Because chitosan is biocompatible, it can therefore be used in drug delivery systems. The development of chitosan-based nanoparticles has also contributed to the significance of chitin as a drug delivery system that can deliver drugs topically. Furthermore, chitin can be used in cancer treatment as a vehicle for delivering cancer drugs to a specific site and has an antiproliferative effect by reducing the viability of cells. Finally, chitosan can be used as a wound dressing in order to promote the faster regeneration of skin epithelial cells and collagen production by fibroblasts. As discussed in this review, chitin and chitosan have diverse applications in the medical field. Recognizing the biomedical applications of these two polymers is essential for future research in tissue engineering and nanobiotechnology.

Chitosan and Chitooligosaccharide: The Promising Non-Plant-Derived Prebiotics with Multiple Biological Activities

Biodegradable chitin is the second-most abundant natural polysaccharide, widely existing in the exoskeletons of crabs, shrimps, insects, and the cell walls of fungi. Chitosan and chitooligosaccharide (COS, also named chitosan oligosaccharide) are the two most important deacetylated derivatives of chitin. Compared with chitin, chitosan and COS not only have more satisfactory physicochemical properties but also exhibit additional biological activities, which cause them to be widely applied in the fields of food, medicine, and agriculture. Additionally, due to their significant ability to improve gut microbiota, chitosan and COS are deemed prospective prebiotics. Here, we introduced the production, physicochemical properties, applications, and pharmacokinetic characteristics of chitosan and COS. Furthermore, we summarized the latest research on their antioxidant, anti-inflammatory, and antimicrobial activities. Research progress on the prebiotic functions of chitosan and COS is particularly reviewed. We creatively analyzed and discussed the mechanisms and correlations underlying these activities of chitosan and COS and their physicochemical properties. Our work enriched people's understanding of these non-plant-derived prebiotics. Based on this review, the future directions of research on chitosan and COS are explored. Collectively, optimizing the production technology of chitin derivatives and enriching understanding of their biological functions will shed more light on their capability to improve human health.

Adipose-derived mesenchymal stem cell-loaded β-chitin nanofiber hydrogel promote wound healing in rats

Because of stem cells are limited by the low efficiency of their cell homing and survival in vivo, cell delivery systems and scaffolds have attracted a great deal of attention for stem cells' successful clinical practice. β-chitin nanofibers (β-ChNF) were prepared from squid pens in this study. Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy proved that β-ChNFs with the diameter of 5 to 10 nm were prepared. β-ChNF dispersion became gelled upon the addition of cell culture medium. Cell culture experiments showed that β-ChNFs exhibited negligible cytotoxicity towards ADSCs and L929 cells, and it was found that more exosomes were secreted by the globular ADSCs grown in the β-ChNF hydrogel. The vivo experiments of rats showed that the ADSCs-loaded β-ChNF hydrogel could directly cover the wound surface and significantly accelerate the wound healing and promote the generation of epithelization, granulation tissue and collagen. In addition, the ADSCs-loaded β-ChNF hydrogel clearly regulated the expressions of VEGFR, α-SMA, collagen I and collagen III. Finally, we showed that ADSCs-loaded β-ChNF hydrogel activated the TGFβ/smad signaling. The neutralization of TGFβ markedly reduced Smad phosphorylation and the expressions of TIMP1, VEGFR and α-SMA. Taken together, these findings suggest that ADSCs-loaded β-ChNF hydrogel promises for treating wounds that are challenge to heal via conventional methods. Graphical abstract.

Wound healing properties of triple cross-linked poly (vinyl alcohol)/methacrylate kappa-carrageenan/chitooligosaccharide hydrogel

To develop an effective and mechanically robust wound dressing, a poly (vinyl alcohol) (PVA)/methacrylate kappa-carrageenan (κ-CaMA) composite hydrogel encapsulated with a chitooligosaccharide (COS) was prepared in a cassette via repeated freeze/thaw cycles, photo-crosslinking, and chemical cross-linking. The chemical, physical, mechanical, in vitro biocompatibility, in vivo wound-healing properties, and antibacterial activity of triple-crosslinked hydrogel were subsequently characterized. The results showed that the PVA/κ-CaMA/COS (Pκ-CaC) hydrogel had a uniformly thick, highly porous three-dimensional architecture with uniformly distributed pores, a high fluid absorption, and retention capacity without disturbing its mechanical stability, and good in vitro biocompatibility. Macroscopic images from the full-thickness skin wound model revealed that the wounds dressed with the proposed Pκ-CaC hydrogel were completely healed by day 14, while the histomorphological results confirmed full re-epithelization and rapid skin-tissue remodeling. This study thus indicates that the composite Pκ-CaC hydrogel has significant potential for use as a wound dressing.

Production and Characterization of Chitooligosaccharides: Evaluation of Acute Toxicity, Healing, and Anti-Inflammatory Actions

The search for promising biomolecules such as chitooligosaccharides (COS) has increased due to the need for healing products that act efficiently, avoiding complications resulting from exacerbated inflammation. Therefore, this study aimed to produce COS in two stages of hydrolysis using chitosanases derived from Bacillus toyonensis. Additionally, this study aimed to structurally characterize the COS via mass spectrometry, to analyze their biocompatibility in acute toxicity models in vivo, to evaluate their healing action in a cell migration model in vitro, to analyze the anti-inflammatory activity in in vivo models of xylol-induced ear edema and zymosan-induced air pouch, and to assess the wound repair action in vivo. The structural characterization process pointed out the presence of hexamers. The in vitro and in vivo biocompatibility of COS was reaffirmed. The COS stimulated the fibroblast migration. In the in vivo inflammatory assays, COS showed an antiedematogenic response and significant reductions in leukocyte migration, cytokine release, and protein exudate. The COS healing effect in vivo was confirmed by the significant wound reduction after seven days of the experiment. These results indicated that the presence of hexamers influences the COS biological properties, which have potential uses in the pharmaceutical field due to their healing and anti-inflammatory action.

Ovarian Cell Encapsulation in an Enzymatically Crosslinked Silk-Based Hydrogel with Tunable Mechanical Properties

An artificial ovary is a promising approach for preserving fertility in prepubertal girls and women who cannot undergo current cryopreservation strategies. However, this approach is in its infancy, due to the possible challenges of creating a suitable 3D matrix for encapsulating ovarian follicles and stromal cells. To maintain the ovarian stromal cell viability and proliferation, as a first step towards developing an artificial ovary, in this study, a double network hydrogel with a high water swelling capacity (swelling index 15–19) was developed, based on phenol conjugated chitosan (Cs-Ph) and silk fibroin (SF) through an enzymatic crosslinking method using horseradish peroxidase. The addition of SF (1%) to Cs (1%) decreased the storage modulus (G’) from 3500 Pa (Cs1) to 1600 Pa (Cs-SF1), and the hydrogels with a rapid gelation kinetic produced a spatially homogeneous distribution of ovarian cells that demonstrated 167% proliferation after 7 days. This new Cs-SF hydrogel benefits from the toughness and flexibility of SF, and phenolic chemistry could provide the potential microstructure for encapsulating human ovarian stromal cells.

Electrospun porous bilayer nano-fibrous fish collagen/PCL bio-composite scaffolds with covalently cross-linked chitooligosaccharides for full-thickness wound-healing applications

The development of tissue-engineered biodegradable artificial tissue substitutes with extracellular matrix-mimicking properties that govern the interaction between the material and biological environment is of great interest in wound-healing applications. In the present study, novel bilayer nanofibrous scaffolds composed of fish collagen (FC) and poly(ε-caprolactone) (PCL) were fabricated using electrospinning, with the covalent attachment of chitooligosaccharides (COS) via carbodiimide chemistry. The architecture and fiber diameter of the non-cross-linked nanofibrous scaffolds remained consistent irrespective of the polymer ratio under different electrospinning conditions, but the fiber diameter changed after cross-linking in association with the FC content. Fourier-transform infrared spectroscopy analysis indicated that the blend of biomaterials was homogenous, with an increase in COS levels with increasing FC content in the nanofibrous scaffolds. Based on cytocompatibility analysis (i.e., the cellular response to the nanofibrous scaffolds and their interaction), the nanofibrous scaffolds with high FC content were functionally active in response to normal human dermal fibroblast‑neonatal (NHDF-neo) and HaCaT keratinocyte cells, leading to the generation of a very effective tissue-engineered implant for full-thickness wound-healing applications. In addition to these empirical results, an assessment of the hydrophilicity, swelling, and mechanical integrity of the proposed COS-containing FC-rich FC/PCL (FCP) nanofibrous scaffolds confirmed that they have significant potential for use as tissue-engineered skin implants for rapid skin regeneration.

Vaginal Administration of Contraceptives

While contraceptive drugs have enabled many people to decide when they want to have a baby, more than 100 million unintended pregnancies each year in the world may indicate the contraceptive requirement of many people has not been well addressed yet. The vagina is a well-established and practical route for the delivery of various pharmacological molecules, including contraceptives. This review aims to present an overview of different contraceptive methods focusing on the vaginal route of delivery for contraceptives, including current developments, discussing the potentials and limitations of the modern methods, designs, and how well each method performs for delivering the contraceptives and preventing pregnancy.

Intestinal Population in Host with Metabolic Syndrome during Administration of Chitosan and Its Derivatives

Chitosan and its derivatives can alleviate metabolic syndrome by different regulation mechanisms, phosphorylation of AMPK (AMP-activated kinase) and Akt (also known as protein kinase B), suppression of PPAR-γ (peroxisome proliferator-activated receptor-γ) and SREBP-1c (sterol regulatory element–binding proteins), and translocation of GLUT4 (glucose transporter-4), and also the downregulation of fatty-acid-transport proteins, fatty-acid-binding proteins, fatty acid synthetase (FAS), acetyl-CoA carboxylase (acetyl coenzyme A carboxylase), and HMG-CoA reductase (hydroxy methylglutaryl coenzyme A reductase). The improved microbial profiles in the gastrointestinal tract were positively correlated with the improved glucose and lipid profiles in hosts with metabolic syndrome. Hence, this review will summarize the current literature illustrating positive correlations between the alleviated conditions in metabolic syndrome hosts and the normalized gut microbiota in hosts with metabolic syndrome after treatment with chitosan and its derivatives, implying that the possibility of chitosan and its derivatives to serve as therapeutic application will be consolidated. Chitosan has been shown to modulate cardiometabolic symptoms (e.g., lipid and glycemic levels, blood pressure) as well as gut microbiota. However, the literature that summarizes the relationship between such metabolic modulation of chitosan and prebiotic-like effects is limited. This review will discuss the connection among their structures, biological properties, and prebiotic effects for the treatment of metabolic syndrome. Our hope is that future researchers will consider the prebiotic effects as significant contributors to the mitigation of metabolic syndrome.

Inverse Poly-High Internal Phase Emulsions Poly(HIPEs) Materials from Natural and Biocompatible Polysaccharides

This paper shows one of the few examples in the literature on the feasibility of novel materials from natural and biocompatible polymers like inulin (INU) or glycol chitosan (GCS) templated by the formation of o/w (inverse) high internal phase emulsion (HIPE). To the best of our knowledge, this is the first example of inverse polyHIPEs obtained from glycol chitosan or inulin. The obtained polyHIPEs were specifically designed for possible wound dressing applications. The HIPE (pre-crosslinking emulsion) was obtained as inverse HIPE, i.e., by forming a cream-like 80:20 v/v o/w emulsion by using the isopropyl myristate in its oil phase, which is obtained from natural sources like palm oil or coconut oil. The surfactant amount was critical in obtaining the inverse HIPE and the pluronic F127 was effective in stabilizing the emulsion comprising up to 80% v/v as internal phase. The obtained inverse HIPEs were crosslinked by UV irradiation for methacrylated INU or by glutaraldehyde-crosslinking for GCS. In both cases, inverse poly-HIPEs were obtained, which were physicochemically characterized. This paper introduces a new concept in using hydrophilic, natural polymers for the formation of inverse poly-HIPEs.