The effect of the chitosan-collagen membrane on wound healing process in rat mandibular defect

Investigation of GOx Stability in a Chitosan Matrix: Applications for Enzymatic Electrodes

In this study, we designed a new biosensing membrane for the development of an electrochemical glucose biosensor. To proceed, we used a chitosan-based hydrogel that entraps glucose oxidase enzyme (GOx), and we crosslinked the whole matrix using glutaraldehyde, which is known for its quick and reactive crosslinking behavior. Then, the stability of the designed biosensors was investigated over time, according to different storage conditions (in PBS solution at temperatures of 4 °C and 37 °C and in the presence or absence of glucose). In some specific conditions, we found that our biosensor is capable of maintaining its stability for more than six months of storage. We also included catalase to protect the biosensing membranes from the enzymatic reaction by-products (e.g., hydrogen peroxide). This design protects the biocatalytic activity of GOx and enhances the lifetime of the biosensor.

Effect of Chitosan Deacetylation on Its Affinity to Type III Collagen: A Molecular Dynamics Study

The ability to form strong intermolecular interactions by linear glucosamine polysaccharides with collagen is strictly related to their nonlinear dynamic behavior and hence bio-lubricating features. Type III collagen plays a crucial role in tissue regeneration, and its presence in the articular cartilage affects its bio-technical features. In this study, the molecular dynamics methodology was applied to evaluate the effect of deacetylation degree on the chitosan affinity to type III collagen. The computational procedure employed docking and geometry optimizations of different chitosan structures characterized by randomly distributed deacetylated groups. The eight different degrees of deacetylation from 12.5% to 100% were taken into account. We found an increasing linear trend (R2 = 0.97) between deacetylation degree and the collagen-chitosan interaction energy. This can be explained by replacing weak hydrophobic contacts with more stable hydrogen bonds involving amino groups in N-deacetylated chitosan moieties. In this study, the properties of chitosan were compared with hyaluronic acid, which is a natural component of synovial fluid and cartilage. As we found, when the degree of deacetylation of chitosan was greater than 0.4, it exhibited a higher affinity for collagen than in the case of hyaluronic acid.

Chitosan Membrane Containing Copaiba Oil (Copaifera spp.) for Skin Wound Treatment

The interaction of copaiba oil in the polymer matrix of chitosan can produce a favorable synergistic effect and potentiate properties. Indeed, the bioactive principles present in copaiba oil have anti-inflammatory and healing action. In the present work, chitosan membranes containing different contents of copaiba oil copaíba (0.1, 0.5, 1.0 and 5.0% (v/v)) were for the first time investigated. The membranes were developed by the casting method and analyzed for their morphology, degree of intumescence, moisture content, contact angle, Scanning Electron Microscope, and X-ray diffractometry. These chitosan/copaiba oil porous membranes disclosed fluid absorption capacity, hydrophilic surface, and moisture. In addition, the results showed that chitosan membranes with the addition of 1.0% (v/v) of copaiba oil presented oil drops with larger diameters, around 123.78 μm. The highest fluid absorption indexes were observed in chitosan membranes containing 0.1 and 0.5% (v/v) of copaiba oil. In addition, the copaiba oil modified the crystalline structure of chitosan. Such characteristics are expected to favor wound treatment. However, biological studies are necessary for the safe use of chitosan/copaiba oil membrane as a biomaterial.

Bone regeneration using Wollastonite/β-TCP scaffolds implants in critical bone defect in rat calvaria

In order to provide favorable conditions for bone regeneration, a lot of biomaterials have been developed and evaluated, worldwide. Composite biomaterials have gained notoriety, as they combine desirable properties of each isolated material. Thus, in this research, bone repair capacity of three developed formulations of ceramic scaffolds were evaluated histomorphometrically, after implantation. Scaffolds were based on wollastonite (W) andβ-tricalcium phosphate (β-TCP) composites in three different ratios (wt.%). ThirtyWistarrats were randomly assigned to three experimental groups: W-20 (20 W/80β-TCP wt.%), W-60 (60 W/40β-TCP wt.%), and W-80 (80 W/20β-TCP wt.%), evaluated by optical microscopy at biological tests after 15 and 45 days of implantation. Throughout the study, the histological results evidenced that the scaffolds remained at the implantation site, were biocompatible and presented osteogenic potential. The percentage of neoformed mineralized tissue was more evident in the W-20 group (51%), at 45 days. The composite of the W-80 group showed more evident biodegradation than the biomaterials of the W-20 and W-60 groups. Thus, it is concluded that the scaffold containing 20 W/80β-TCP (wt.%) promoted more evident bone formation, but all composites evaluated in this study showed notorious bioactivity and promising characteristics for clinical application.

Optimization and evaluation of ciprofloxacin-loaded collagen/chitosan scaffolds for skin tissue engineering

A novel ciprofloxacin-loaded collagen-chitosan scaffold was developed for the treatment of wound using freeze drying method. The average pore size and porosity of developed scaffold was found to be around 125 µm and 91 ± 0.56%. Moreover, swelling, degradation and mechanical tests profile supported the suitability of scaffold for wound healing process. The scaffold has high degree of hemocompatibility towards the blood and promotes the growth, migration and proliferation of fibroblast. The developed scaffold exhibits antibacterial properties and was found to be efficient against the Gram-negative (E.coli) and Gram-positive (Staphylococcus aureus) bacteria hence can be used for wound healing applications. In vivo study demonstrated that the scaffold not only escalated the tissue regeneration time but also accelerated the wound healing process compared to control. The histological studies revealed better granulation, vascularization, and remodeling of extracellular matrix along with regeneration of epidermal and dermal layer of skin. Overall, the obtained results suggested that the developed skin tissue constructs possess the enormous potential for tissue regeneration and might be a suitable biomaterial for skin tissue engineering applications.

A glimpse on the function of chitosan as a dental hemostatic agent

Managing a bleeding patient can be a challenge during dental surgery. Profuse hemorrhage due to platelet defects, coagulation disorders, vascular anomalies, medication-induced patients, as well as inherited bleeding ailments result in soft tissue hematoma, septic shock, compromised airway, and in some severe cases, death could occur. A vast array of surgical hemostatic agents are available to stop bleeding, including chitosan-based hemostatic agents. Chitosan has an advantage over other topical hemostatic materials for its ability to promote shorter bleeding times and assist in healing. Massive behind-the-scene research and development efforts are ongoing to increase the performance of chitosan as a hemostatic agent. Numerous studies on chitosan use in dental hemostasis have registered it as being safe, biodegradable, biocompatible, promoting healing, antimicrobial and bioactive. This article reviews the application of chitosan in managing hemostasis in dental patients.