Preparation Of Bacterial Cellulose/Poly N-isopropyl Acrylamide Composite Hydrogel And Drug Loading Study

Bacterial cellulose (BC) is a natural biopolymer with a unique nanofiber network structure. In recent years, because of its high crystallinity, high water retention, good biological activity, biodegradability, and biocompatibility, it has become the focus of new biomedical materials. However, as a medical hydrogel material, there are obvious shortcomings with BC. Due to the hydrogen bonds between the filaments, it can not restore the swelling property after dehydration in the air, which not only affects the function of the materials, but also brings troubles to the modification of BC. So chemical, physical and other methods are often useed to improve the properties of bacterial cellulose.N-isopropyl acrylamide (NIPAM) is a temperature-sensitive compound. The Poly N-isopropyl acrylamide (PNIPAM) hydrogel has a low critical solution temperature (LCST). When temperature is below its LCST, PNIPAM hydrogels highly swollen, but when temperature is above the LCST, the hydrogel shrink violently. The LCST is similar to the human physiological temperature and is slightly higher than room temperature, which is easy to be controlled. Therefore the polymer has many excellent features and has been increasingly widely used in enzyme immobilization, biosensors and catalysis, separation and purification of proteins, as well as drug targeting and release.This paper introduces that with bacterial cellulose as matrix, using radical polymerization method to obtain bacterial cellulose/poly N-isopropyl acrylamide (BC/PNIPAM) composite hydrogel material, and examine the effects of different concentrations of monomer NIPAM on the composite morphology, chemical structure, physical properties including thermal stability and regularity in terms of drug diffusion at different temperatures. Asian norvegicus abdominal skin was used as a skin mode and sodium benzoate was used as a drug mode, the process of in vitro transdermal drug and. law in transdermal drug diffusion were studied. The effects of enhancers menthol and borneol on drug diffusion at different concentrations were investigated.The results showed that with the increase of NIPAM monomer concentration, the network structure BC/PNIPAM composite became dense. Diffusion of sodium benzoate as a drug mode through the composite film was more in line with Higuchi drug diffusion models. Under same concentration, the diffusion of single BC film was fastest, followed by the diffusion rate of the composite film at 37℃, but diffusion at 10℃ was slowest. Drug diffusion rate of high concentration monomer-polymerized composite hydrogel was slower than that of low concentration monomer-polymerized one. Addition of accelerator menthol or borneol could promote the penetration of sodium benzoate in skin. Menthol of 2% and borneol of 5% showed better effect. The results indicated that high concentration NIPAM monomer-polymerized BC/ PNIPAM comosite hydrogel had a better drug diffusion effect, therefore this composite hydrogel would have a great potenial in the application field of controlled drug release, such as cooling paste and analgesic paste.