In this study, the effect of the ionic cross-linking mode on the ability to control physical properties and in vitro release behavior of the dexamethasone (DEX) drug from chitosan (CS) and chitosan/hydroxyapatite (CS/HA) beads was investigated. CS solutions without and with HA and DEX were dripped into two coagulation solutions, prepared with a non-toxic ionic crosslinker (sodium tripolyphosphate, TPP) and distilled water, one at pH = 9.0 and other at pH = 6.0. Optical microscopy (OM) and scanning electron microscopy (SEM) results showed changes on the surface topology of the beads, with a reduction of roughness for beads prepared at pH = 6.0 and an increase for the one prepared at pH = 9.0. The diameter and sphericity of the beads prepared at pH = 6.0 proved more uniform and had a larger pore size with a good interconnectivity framework. Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) suggested a higher crosslinking degree for beads prepared at pH = 6.0, corroborated by X-ray diffraction profiles (XRD) analysis that indicated a decrease in the crystalline structure for such beads. In in vitro drug release data, all beads presented a sustained release during the studied period (24 h). The drug release rate was affected by the pH of the coagulation solution used in the preparation of the beads. The in vitro kinetics of the release process was of the Peppas–Sahlin model, controlled by both diffusion and relaxation of polymer chains or swelling (anomalous transport mechanism). Our results suggest that DEX-loaded CS/HA beads, crosslinked in TPP coagulation solution at pH = 9.0, led to a decrease in the DEX release rate and prolonged the release period. Thus, this composition might have prospective as a functional material for bone and cartilage tissue engineering.

Episiotomy is an obstetric technique that consists of making an incision in the perineum during vaginal childbirth, to facilitate the baby to pass through. After delivery, the perineal region is sutured with absorbable threads to heal the cut. However, are frequent reports of pain, infections, and dyspareunia after the execution of this technique. In this context, the use of biomaterials becomes relevant as they promote faster and safer tissue repair, making it an attractive alternative for the healing process of episiotomy. Based on the physical-chemical and biological properties of chitosan and Aloe vera, this research developed three different vaginal gels, with the purpose of promoting tissue regeneration and infection prevention post-episiotomy. Chitosan solutions with concentrations of 5% w/v were prepared by dissolving the chitosan powder in 2% v/v aqueous solution of acetic acid. After the extraction and processing of the mucilage, the pulp of the Aloe vera leaf was added to the chitosan gel in the proportions of 1, 2, and 3% v/v. All formulations were neutralized by the slow drip technique of a neutralizing solution of sodium hydroxide (2 M). The compositions were analyzed according to their organoleptic aspect, optical microscopy, spreadability, hydrogen potential, absorption spectroscopy, cytotoxicity, and rheological behavior. Based on the results obtained, it was possible to conclude that gels produced have the potential to be used as vaginal gels.

Chitosan is a natural, biodegradable, non-toxic and biocompatible polymer, with characteristics such as a healing, hemostatic, antimicrobial agent, among others. Therefore, the aim of this study is to develop a tubular chitosan device for use as a prosthetic coating application in vascular surgery. The chitosan wires were obtained by the spinning method in a 2M sodium hydroxide coagulant solution (NaOH) and used in the form of wires and screens as a reinforcement structure to obtain the tubes. In order to characterize the tubes, optical microscopy, contact angle, degree of swelling, in vitro biodegradation, cytotoxicity and tensile strength were used. The results indicated that the tubes have uniformity over the entire length and as for the resistance to the trace, the tube reinforced with mesh presented greater deformation, while the tube reinforced with wire presented a higher value of rupture stress. The degree of swelling was higher in chitosan tubes with mesh. As for the biodegradation test, it was observed that the lysozyme samples showed greater loss of mass and the cytotoxicity test confirmed the cell viability of the material, concluding that the tubes reinforced with chitosan wires are promising for use in vascular surgeries.