Synthesis And Behavior Of The Environmental Sensitivity Keratin-based Polymer Hydrogels

Feather keratin, as a natural polymer material, is not only a rich inexpensive source, but also has a good biocompatibility and biodegradability. Because it’s more cystine content, Feather keratin has physicochemical properties, but it is easily protease and has poor mechanical properties. Modifying its structure can broaden the application areas of Feather keratin. In this paper, Feather keratin(FK) as raw material, with polysaccharide sodium alginate(SA), beta hydroxy ethyl methacrylate(HEMA) and itaconic acid(IAc) and N-isopropyl acrylamide(Ni PA) as functional monomer, to prepare the environmental sensitivity intelligent hydrogels. The structure, thermal stability and hydrogels surface morphology of copolymers has been characterized by using flourier-infrared spectrometry(FT-IR), thermogravimetric analysis(TG) and scanning electron microscope(SEM), respectively.Firstly, the structure of keratin and its classification and extraction method were introduced. Then, being acted as natural polymer materials, keratin modification, material preparation and its application fields were reviewed. Keratin materials were modified commonly used physical blend and grafted polymerization methods, and preparation of environmentally friendly composite materials, while the degradation of keratin mainly adopt microbial and enzymatic hydrolysis. Owing to the keratin hydrolysis can produce many kinds of amino acid; it has good biocompatibility and biodegradability. Keratin was used as medical materials, drug release materials, daily materials, food packaging materials, plastic materials. It was also used as a good adsorbent of heavy metal ions and waste water decoloring agent. In a word, the keratin materials development and application has a very promising future.Secondly, the use of sequential interpenetrating network method, the choice of their common good solvent urea solution as the reaction medium, the keratin(FK) and hydroxyethyl methacrylate(HEMA) were blended. At the same time the choice of glutaraldehyde(GA) as a crosslinking agent FK, water-soluble redox initiator APS used to initiate polymerization of monomer HEMA, with the MBA as crosslinking agent, making FK and HEMA crosslinked polymeric form an interpenetrating network. The structure, thermal stability and hydrogels surface morphology of polymers has been characterized by using FT-IR, TG and SEM, respectively. Found the hydrogels has porous structure. We studied the FK/PHEMA interpenetrating polymer network hydrogels swelling properties and re-swelling properties in different media. And the results show a good performance of the swelling properties and re-swelling properties. The vitro drug release behavior of FK/PHEMA is investigated under different environments by using drug molecules such as Small molecule(RB), doxorubicin hydrochloride(Dox ? HCl) and macromolecules(BSA). Find FK/PHEMA for small molecule RB and Dox ? HCl drug loading efficiency was 60.9%, 63.2% and macromolecular BSA drug loading efficiency is 44.5%. When the p H=8.4, the FK/PHEMA interpenetrating polymer network hydrogels release has the best performance at body temperature(37℃), with the cumulative release rate up to 90.9%. Therefore, FK/PHEMA interpenetrating polymer network hydrogels is expected as a p H sensitive drug carrier.Thirdly, Feather keratin(FK) as a biological polymer materials, selection of inexpensive, non-toxic and stable itaconic acid(IAc) for acid-sensitive monomer, N-isopropyl acrylamide(Ni PA) for temperature-sensitive monomer, in the presence of crosslinking agent(MBA), carries on the polymerization reaction. First, the poly-N-isopropylacrylamide(PNi PA) and FK binding, is further introduced PIAc, preparation has interpenetrating network structure double-sensitive hydrogels(FK/PNi PA-PIAc). The vitro drug release behavior of FK/PNi PA-PIAc is investigated under different environments by using drug molecules such as small molecule(RB)、doxorubicin hydrochloride(Dox ? HCl) and macromolecules(BSA). Research FK/PNi PA-PIAc hydrogels at different temperatures and p H medium for drug release properties. At 37 ℃, when the p H=7.4, the FK/PNi PA-PIAc double sensitive hydrogels for RB the maximum cumulative release rate up to 83.5% and the Dox? HCl maximum cumulative release up to 93.3%. Finally, the Feather keratin and p H-sensitive polysaccharide alginate(SA), N-isopropyl acrylamide(Ni PA) for temperature-sensitive monomer, by polymerization reaction the p H and temperature responsive hydrogels were obtained. The SA content on the hydrogels structure, morphology and swelling ratio were studied. The vitro drug release behavior of FK/SA and FK/SA-PNi PA are investigated under different environments by using drug molecules such as Small molecule(RB, Dox ? HCl) and macromolecules(BSA). Research FK/SA and FK/SA-PNi PA hydrogels at different temperatures and p H medium for drug release properties. At 37℃, when the p H=7.4, the FK/SA hydrogels for RB the maximum cumulative release rate up to 85.4% and the BSA maximum cumulative release up to 73.8%. At 37℃, when the p H=7.4, the FK/SA-PNi PA hydrogels for RB the maximum cumulative release rate up to 82.6% and the BSA maximum cumulative release up to 74.0%, and the Dox ? HCl maximum cumulative release up to 78.6%. At 42℃, when the p H = 7.4, the FK/SA-PNi PA hydrogels for RB the maximum cumulative release rate up to 91.0% and the BSA maximum cumulative release up to 81.3%, and the Dox ? HCl maximum cumulative release up to 90.4%.To be concluded, the paper prepares protein-based polymer material have a good release property in vitro. This research broadens the study range of natural polymer protein-based drug carrier. There are no doubts that it will have a bright application prospect in biomedical field.