Chitosan-based glycerol-plasticized membranes: bactericidal and fibroblast cellular growth properties

Chitosan-based structures for skin repair: A literature review

The use of chitosan in technological and biomedical applications has gained significant relevance due to its functional properties. Among its biological activities, its hemostatic, analgesic, antibacterial and anti-inflammatory activities make this natural biopolymer one of the most promising in the development of structures for skin repair. Its application and effects can be optimized by exploring efficient structuring techniques. In this context, this review is based on scientific evidence reported in the last decade regarding the development and use of chitosan-based structures in the skin repair process to show the most common structuring methods, the main mechanisms of action of chitosan, and its potential applications in skin repair processes. Additionally, this article brings a compilation of scientific and commercial works on the use of chitosan-based structures, in addition to vitro and/or in vivo results.

A novel rat model for studying bilateral cavernous nerve damage in vivo: exploring the potential of chitosan-blended membranes for nerve regeneration post-radical prostatectomy

BACKGROUND

The primary treatment for localized prostate cancer involves radical prostatectomy (RP) often resulting in iatrogenic damage to the periprostatic neurovascular bundles (NVB), leading to erectile dysfunction. The current study devised an experimental model involving bilateral cavernous nerve (CN) lesions in rats to replicate nerve damage close to the injury of the NVB in humans following radical prostatectomy.

METHODS

Fifteen adult male Wistar rats were divided as follows: control rats without surgery (CTRL group); rats underwent bilateral resection of 2 mm of CN repaired with a glycerol-blended chitosan membranes (CS-MEM group); rats underwent a total resection of both CN and major pelvic ganglion (RES group). Two months after surgery, membranes with regenerated nerves were analyzed morphologically, and for gene and protein expression for the evaluation of nerve regeneration and vascularization. Rat penises were assessed for smooth muscle content, morphology, and tissue arrangement. Primary sensory neuron cultures and DRG explants were cultured on micro-grooved chitosan-blended membranes, to evaluate axonal orientation on different topographies.

RESULTS

Regenerated nerve fibers and newly formed vessels colonized the whole CS-membrane. The regenerative process was also confirmed by gene and protein expression analyses. The target organ exhibited remodeling of smooth muscle tissue around sinusoidal spaces, indicating potential restoration of cavernous tissue. The quantitative analyses of α-actin smooth muscle (α-SMA) expression in CS-MEM groups displayed α-SMA protein signals comparable to controls. In-vitro experiments on micro-patterned membranes displayed oriented axonal growth, showing valuable insights into the ways in which topographical features can be considered for a more effective performance in vivo.

CONCLUSIONS

Chitosan-blended membranes promote nerve fiber regeneration in an in-vivo model of nerve lesion that resembles the damage to the NVB occurring in men after radical prostatectomy. These results highlight the promising potential of this device in the clinical urological field, thus suggesting that the application of orientated micro-patterned membranes could further improve nerve regeneration.

Preparation of antibacterial composite film based on arginine-modified chitosan and its application in the preservation of ready-to-eat sea cucumber

An edible composite film was developed and applied for ready-to-eat sea cucumber storage to improve the product quality. The PAC film base is first prepared by mixing 0.5 % glycerin (GL) with 4 % polyvinyl alcohol (PVA) and 1 % arginine-modified chitosan (Arg-CTS) in the same volume. After the addition of nano-ZnO (ZnO) and thymol (Thy) to the PAC film base, the mechanical properties and functions were tested. Compared to the PAC film, the PAC-ZnO-ThyH composite film showed a 1.34-fold increase in the DPPH scavenging rate and a 2.19-fold increase in the ABTS scavenging rate. Contrary to the PAC film, the inhibition zone diameter of Escherichia coli and Staphylococcus aureus significantly increased by 2.35 and 4.08 folds in the PAC-Zno-ThyH film, respectively. After applying the PAC-ZnO-ThyH film to store ready-to-eat sea cucumber for 10 days, there was a significant reduction in weight loss, total volatile basic nitrogen (TVB-N), and lipid oxidation levels to 1.47 and 1.26 folds to the Ctrl group. After preservation, the hardness and chewiness of ready-to-eat sea cucumber were maintained at 1079.62 ± 138.86 N and 913.73 ± 175.79 N, respectively. The novel PAC-ZnO-ThyH composite film can be used as an active food packaging for promising seafood applications.

Glycerol-blended chitosan membranes with directional micro-grooves and reduced stiffness improve Schwann cell wound healing

Regenerative medicine is continuously looking for new natural, biocompatible and possibly biodegradable materials, but also mechanically compliant. Chitosan is emerging as a promising FDA-approved biopolymer for tissue engineering, however, its exploitation in regenerative devices is limited by its brittleness and can be further improved, for example by blending it with other materials or by tuning its superficial microstructure. Here, we developed membranes made of chitosan (Chi) and glycerol, by solvent casting, and micro-patterned them with directional geometries having different levels of axial symmetry. These membranes were characterized by light microscopies, atomic force microscopy (AFM), by thermal, mechanical and degradation assays, and also testedin vitroas scaffolds with Schwann cells (SCs). The glycerol-blended Chi membranes are optimized in terms of mechanical properties, and present a physiological-grade Young's modulus (≈0.7 MPa). The directional topographies are effective in directing cell polarization and migration and in particular are highly performant substrates for collective cell migration. Here, we demonstrate that a combination of a soft compliant biomaterial and a topographical micropatterning can improve the integration of these scaffolds with SCs, a fundamental step in the peripheral nerve regeneration process.

Tailored chitosan/glycerol micropatterned composite dressings by 3D printing for improved wound healing

Wound infection control is a primary clinical concern nowadays. Various innovative solutions have been developed to fabricate adaptable wound dressings with better control of infected wound healing. This work presents a facile approach by leveraging 3D printing to fabricate chitosan/glycerol into composite dressings with tailored micropatterns to improve wound healing. The bioinks of chitosan/glycerol were investigated as suitable for 3D printing. Then, three tailored micropatterns (i.e., sheet, strip, and mesh) with precise geometry control were 3D printed onto a commercial dressing to fabricate the micropatterned composite dressings. In vitro and in vivo studies indicate that these micropatterned dressings could speed up wound healing due to their increased water uptake capacity (up to ca. 16-fold@2 min), benign cytotoxicity (76.7 % to 90.4 % of cell viability), minor hemolytic activity (<1 %), faster blood coagulation effects (within 76.3 s), low blood coagulation index (14.5 % to 18.7 % @ 6 min), enhanced antibacterial properties (81.0 % to 86.1 % against S. aureus, 83.7 % to 96.5 % against E. coli), and effective inhibition of wound inflammation factors of IL-1β and TNF-α. Such tailored micropatterned composite dressing is facile to obtain, highly reproducible, and cost-efficient, making it a promising implication for improved and personalized contaminated wound healing.

Chitosan and chitosan/turmeric-based membranes for wound healing: Production, characterization and application

In the present study, chitosan and chitosan/turmeric-based membranes were produced, characterized and applied in in vivo experiments showing the applicability for skin wound repair. Chitosan 1 % (w/v), chitosan + glycerol 30 % (w/w) and chitosan + glycerol 30 % + turmeric 1.5 % (w/w) membranes were produced through the casting technique. Self-sustainable, homogeneous, and flexible membranes were obtained from all materials tested. The FTIR spectra showed the main vibrational bands for materials used in the chemical groups. The membranes containing glycerol are more flexible than those formed with pure chitosan. Membranes formed with glycerol and glycerol/turmeric are more hydrophilic compared to the membranes formed by pure chitosan. The in vivo results showed that the group who received the chi/gly/turmeric membrane had a statistically greater reduction in the injured area, as well as a better healing process in the histological analysis compared to the other experimental groups. The material developed here is from a natural source, low cost and easy to apply and can accelerate the process of repairing skin lesions.

Improving the Durability of Chitosan Films through Incorporation of Magnesium, Tungsten, and Graphene Oxides for Biomedical Applications

Bacterial infections that cause chronic wounds provide a challenge to healthcare worldwide because they frequently impede healing and cause a variety of problems. In this study, loaded with tungsten oxide (WO3 ), Magnesium oxide (MgO), and graphene oxide (GO) on chitosan (CS) membrane, an inexpensive polymer casting method was successfully prepared for wound healing applications. All fabricated composites were characterized by X-ray powder diffraction (XRD), Fourier transforms infrared spectroscopy (FT-IR), and thermogravimetric analysis (TGA). A scanning electron microscope (SEM) was used to study the synthesized film samples' morphology as well as their microstructure. The formed WO3/MgO@CS shows a great enhancement in the UV/VIS analysis with a highly intense peak at 401 nm and a narrow band gap (3.69 eV) compared to pure CS. The enhanced electron-hole pair separation rate is responsible for the WO3/MgO/GO@CS scaffold's antibacterial activity. Additionally, human lung cells were used to determine the average cell viability of nanocomposite scaffolds and reached 121 % of WO3 /MgO/GO@CS nanocomposite, and the IC50 value was found to be 1654 μg/mL. The ability of the scaffold to inhibit the bacteria has been tested against both E. coli and S. aureus. The 4th sample showed an inhibition zone of 11.5±0.5 mm and 13.5±0.5 mm, respectively. These findings demonstrate the enormous potential for WO3 /MgO/GO@CS membrane as wound dressings in the clinical management of bacterially infected wounds.

Construction of chitosan-based supramolecular biofilm material for wound dressing based on natural deep eutectic solvents

Bacterial infection is still one of the main problems observed in the clinical process of wound healing, so the development of new multifunctional biocompatible materials is an urgent clinical need. A kind of supramolecular biofilm crosslinked by hydrogen bond between natural deep eutectic solvent and chitosan was studied and successfully prepared to reduce bacterial infection. Its killing rates of Staphylococcus aureus and Escherichia coli can reach 98.86 % ± 1.90 % and 99.69 % ± 0.53 %, and it can be degraded in both soil and water, showing excellent biocompatibility and biodegradability. In addition, the supramolecular biofilm material also has the UV barrier property, which can effectively avoid the secondary injury of UV to the wound. Interestingly, the cross-linking effect of hydrogen bond makes the biofilm have a more compact structure and rough surface, and gives the biofilm strong tensile properties. Overall, owing to these unique advantages, NADES-CS supramolecular biofilm has great potential for medical applications, laying the foundation for the realization of sustainable polysaccharide materials.

Controlled Release of Tea Tree Oil from a Chitosan Matrix Containing Gold Nanoparticles

Chitosan is a biopolymer that, due to its versatile bioactive properties, has applications in several areas, including food, medicine and pharmaceuticals. In the field of tissue engineering, chitosan can be used, for example, as a dressing to treat wounds or dermal damage, such as burns or abrasions. This work deals with the controlled release of tea tree oil from chitosan-based polymeric films and droplets containing gold nanoparticles (AuNP). AuNPs were successfully incorporated into the chitosan matrix using two different approaches. Both solutions were loaded with tea tree oil, and from these solutions, it was possible to obtain drop-cast films and droplets. The controlled release of oil in water was performed both in the films and in the droplets. The addition of AuNP in the controlled release system of melaleuca oil favored a release time of around 25 h. A series of experiments was carried out to investigate the effects of different reaction temperatures and acetic acid concentrations on the formation of AuNPs in the presence of chitosan. For this purpose, images of the AuNP films and droplets were obtained using transmission electron microscopy. In addition, UV-vis spectra were recorded to investigate the release of tea tree oil from the different samples.