The 23 rd PPC Symposium on Petroleum, Petrochemicals, and Polymers and The 8 th Research Symposium on Petrochemical and Materials Technology Tuesday May 23, 2017, Pathumwan Princess Hotel, Bangkok, Thailand Page 1 THERMO-RESPONSIVE PROPERTIES OF HYDROGEL OF GALLAN GUM/METHYLCELLULOSE SYSTEM FOR EFFECTIVE CAVITY WOUND HEALING Nattakarn Wankama a , Pongpol Ekabutr a , Pitt Supaphol a a The Petroleum and Petrochemical College, Chulalongkorn University Keywords : Thermo-responsive hydrogel, gellan gum, gelation properties ABSTRACT Cavity wound is one of the complexity of clinical managements. In general, the wound care process still use soaked gauze for dressing and packing cavity wound. This approach is point to be concern for patient because it is uncomfortable and unconform to the wound site. However, In-situ hydrogel formation that undergo sol-gel transitions response to temperature has been growing interest. In this study, the thermo-responsive injectable hydrogel for using as cavity wound dressing was prepared by physical blend of gellan gum (GG) and methylcellulose (MC) in aqueous solution. The presence of the rheological properties of the blend were systematically observed by a stress-controlled rotational rheometer. The results revealed that GG/MC blends exhibit a board linear viscoelastic region, which require an applied stress lager than 100 Pa to break the network of structure. Not only the gelation temperature but also gelation time of those can be tuned by a ratio of GG and/or MC concentrations. Besides, in-vitro cytotoxicity test on L929 mouse fibroblasts via MTT assay was evaluated to prove that can be used in human tissue. *pitt.s@chula.ac.th INTRODUCTION One of the most sophisticated clinical management wounds is a cavity wound, traditionally packed with soaked gauze direct to the wound site and commonly dressed in alginate fiber in the form of ribbon or rope.(Dinah et al., 2006) These strategies may destroy the tissue that is emerging, which promote wound healing. Moreover, it causes inflammation of the wound and provide poor fit and interface between a wound and wound dressing. Hydrogels are three-dimensional, hydrophilic, polymeric networks capable of imbibing large amounts of water. Their highly hydrated nature resemblances the extracellular matrix and is one of the reasons for their popularity within the biomedical community.(Guvendiren et al., 2012) Thermally responsive injectable hydrogels are particularly interesting because their gelation can be triggered by temperature change and they can easily fill arbitrary shaped defects. (Yu et al., 2008) Additionally, when the temperature is the only stimulus, the need for a chemical initiator system is eliminated, which results in a milder process.(Klouda et al., 2015) Physically blending hydrogels can combine two or more component with complementary properties together. Besides, this are simple preparation and low-cost process. Many studies have been developed. For instance, Shoichet et al. prepared an injectable blend hydrogel system composed of hyaluronic acid (HA) and methylcellulose (MC) for using as drug and cells deliveries.(Caicco et al., 2013, Gupta et al., 2006) Methylcellulose (MC), a water- soluble polymer derived from cellulose, is widely used in biomedical applications. (Thirumala et al., 2013) Its chemical structure is characterized by the presence of both hydrophobic methoxy (–CH 3 O) and hydrophilic hydroxy (–OH) groups. MC- based polymers are capable of self-structuring upon temperature variation,