Journal of Bioactive and Compatible Polymers

Quaternary ammonium chitosan (QCS) is a cationic polymer with high antimicrobial properties, but its cations can cause damage to normal cells. Thus, the biocompatibility of QCS in hydrogel dressings should be concerned. In this study, QCS was used as an additive in the preparation of the carboxymethyl chitosan (CMC) and oxidized hyaluronic acid (OHA) hydrogel, and the effect of its content in the hydrogel on antibacterial and biocompatibility was systematically investigated. First, QCS was mixed at a different ratio with CMC to form a QCS/CMC solution. Then, the QCS/CMC solution was added into the OHA solution to obtain the OHA-CMC/QCS hydrogel, which is a double cross-linked network formed by the Schiff base and electrostatic interaction. With the increase of the QCS content in the hydrogel, its mechanical and antibacterial properties were enhanced. The antibacterial rate of OHA-CMC/QCS5 hydrogel with 5% QCS content against Staphylococcus aureus reached 99.80%, and it also showed biocompatibility under the experimental conditions. This work provides a theoretical basis for the use of QCS to prepare the hydrogels that are both antibacterial and biocompatible. The prepared OHA-CMC/QCS5 hydrogel is an ideal candidate for antimicrobial dressings.

To enhance osteointegration between bone implants and bone tissues in implantation surgery, this study aimed to develop a hydrogel using chitosan and dextran to improve the cell proliferative ability, cell migratory capacity, and cell osteogenic ability. Herein, we developed two different hydrogel compositions with three different amounts of magnesium sulfate to produce six hydrogels for application as a filler for total knee replacement surgery to replace bone cement. The swelling property, degradation behavior, composition, and structure of the hydrogel were systemically investigated. Moreover, an MTT assay, scratch test, and alizarin red S staining were conducted to analyze the cell viability, migratory ability, and osteogenic response after being stimulated by the hydrogel. MC3T3-E1 preosteoblasts exhibited significantly improved cell proliferation, migratory capacity, osteogenesis, and mineralization due to MgSO₄ in the hydrogel. Our work provides insights into the development of biomimetic and osteogenic hydrogels for bone integration in implantation surgery.

Marine beds are an untapped resource of bioactive materials which can be explored for drug delivery applications. In the present study, a hydrogel was developed with an optimal concentration of sodium alginate-chitosan core polyelectrolytic complex loaded with anti-diabetic drug metformin and coated with ĸ-Carrageenan as an efficient oral drug delivery vehicle. The formulation was optimized by changing parameters such as concentration of polymers, amount of cross-linker and the type and amount of coating material. The prepared hydrogels were characterized for their structural integrity using instrumental techniques such as FTIR, XRD, DSC, and SEM while the physical properties were assessed by evaluating its thickness, UV barrier ability and swelling degree. In vitro study demonstrated the influence of presence and type of coating material affecting drug delivery process. The study suggested that coating with 3% ĸ-Carrageenan (A19) was found most suitable for oral drug delivery since it could resist diffusion of drug in the stomach (pH 1.2) so that maximum drug could reach the intestine (pH 7.4) for absorption. Metformin loaded hydrogel (A20) released ~49% drug in the simulated gastric fluid (pH 1.2). In the simulated intestinal fluid (pH 7.4) both the hydrogel exhibited a sustained release pattern lasting for more than 4 h. Investigation of drug release kinetics using different mathematical models showed that Higuchi model was the best fit release model with R² ⩾ 0.973. The results indicated that the prepared hydrogels could be potential drug delivery vehicle toward intestine as well as for extended release to colon targeted drug delivery.

Bone grafts are widely used to improve bone healing but this method is costly and make some serious problems like infection in long-term use. To solve these problems, tissue engineering by using scaffolds made of different materials can be used as a supportive structure to enhance bone healing. In the current study, 3-D chitosan (CS) bone scaffold was developed by freeze-drying techniques for bone tissue engineering. The efficiency of the CS scaffold was improved by loading different concentrations of Hesperidin (Hes). Scaffolds were characterized by different mechanical and biological tests to evaluate their properties. In addition, the effect of scaffolds on bone healing was evaluated by a rat femur defect model. Results showed that the porosity of scaffolds was about 45–257 µm and Hes has a negative effect on the mechanical strength of scaffolds. Also, due to the hydrophilic properties of Hes, the degradation rate increased. Histological and CT-Scan evaluation showed that the treated groups which scaffold loaded with 1% and 10% of Hes were fully replaced by new bone and collagenous matrix compared to control and Hesperidin (0%, 0.01%, 0.1%) treated groups. The Runx2 gene expression was significantly increased by 1% and 10% compared to other groups. These results showed the positive effect of the fabricated scaffold on osteogenesis and bone healing and the possibility of using it in clinical trials.

The development of novel tissue constructs from both natural and synthetic biopolymers has attracted widespread attention among researchers, prior to its excellent outcomes in bone tissue regeneration. This research aims to investigate the biocompatibility of carboxymethyl cellulose (CMC)/sodium alginate (SA) embedded with cellulose nanocrystals (CNC) and its surface response due to the biomineralization process as potential implant material. The CMC/SA were prepared with and without CNC using water as the only solvent. It was then freeze-dried for up to 72 h before being further immersed in simulated body fluid (SBF) for comparative studies. Morphological observation by scanning electron microscope (SEM) showed that CMC/SA/CNC (SBF) displayed a spherical apatite structure amid interconnected porous materials with an average particle diameter between 95 and 148 nm. The apatite crystal indicated the existence of calcium (Ca) and phosphorus (P) elements, which was confirmed by energy dispersive X-ray analysis (EDX). All scaffolds showed a porosity of up to 90.13% with a moderate degradation rate and a water absorption value of up to 1100%. Overall, all scaffolds had open, interconnected pore sizes ranging from 40 to 400 µm. Attenuated total reflection – Fourier Transform Infrared (ATR-FTIR) spectroscopy and thermogravimetric analysis (TGA) curve showed a new existing peak and lower decomposition rate, respectively, for SBF-treated scaffolds. Stress-strain curve disclosed the highest tensile stress of CMC/SA/CNC (SBF) at 16.2 MPa and 15.75% strain effect. Preliminary in vitro cytotoxicity studies performed with human foetal osteoblast (hFOB) cells showed that cytocompatibility was more evident on CMC/SA/CNC (SBF) scaffolds. This study showed that scaffold-embedded CNC with SBF treatment could be hit upon as material selection for bone tissue engineering.