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Background : The aim of this study is to achieve the principles of tissue engineering using biopolymers to be applied in the field of vital endodontic treatment with the aim of stimulating stem cells and engineering and regeneration of dentin tissue. the blend was loaded with the steroidal antiinflammatory drug, dexamethasone, and the porous drug-loaded bio-sponge was produced by lyophilization. Bio-sponge, as a direct pulp capping agent, was histologically studied compared to calcium hydroxide Ca(OH)2 in an animal experiment.Results: The results indicated the effectiveness of the bio-sponge as a direct pulp agent, where the dentin bridge was formed faster than Ca(OH)2 treated samples,. There was no inflammatory response in the pulp tissue throughout the follow-up period.Conclusions : The porous bio-sponge loaded with dexamethasone with a neutral pH resulted in enhancement the odontoblast differentiation from stem cells, resulted in the formation of a renewed dentin bridge without the slightest inflammatory response in the pulp. aminoglycan GAG (13) . ECM is responsible for cellular metabolism and the forming of new tissues since it gives the mechanical and biochemical properties for the formed tissue (14) . ECM plays a crucial role in regulating the expression of the differentiated phenotype and in supporting both migration and proliferation of fibroblast cells (15) .Chitin, the most abundant polysaccharide in nature after cellulose, is synthesized by an enormous number of living organisms, presents in the exoskeleton of crustaceans, insects and fungal cell walls (16) . Chitin consists of a saccharide backbone with β-1,4-linked glucosamine units and characterized by a high availability of acetyl group (17) . Chitin has a cellulose-like structure with the difference of hydroxyl-group replacement by (-NHCOCH 3 ) at the C 2 site (18) . Chitosan is the main derivative of chitin and derived by alkaline deacetylation of chitin (19) . The availability of functional groups allows chemical modifications, making it possible to load and release drugs from chitosan (20) .Chitosan scaffolds with an interconnected porous structure have been shown to be easily manufactured by lyophilization of chitosan solution (21) , and have been widely studied in the bone tissue engineering, and it has been shown that it promotes osteoblast cells growth and deposition of the mineralized matrix by cells (22) . The addition of chitosan molecules to the human bone marrow transplantation medium stimulates bone deposition by promoting cell differentiation (23) . It has been suggested that chitosan enhanced bone formation in vivo through indirect mechanisms (23) , and it can be used as a standard GAG in tissue regeneration processes (24) .Collagen is the most abundant protein in the body and it is the major component in body tissues, it forms also about 30% of total proteins in mammals (25) . About 28 types of collagen have been identified (26) , among which, the type-I collagen is the prevalent type and it is the main component of the ECM (27) ....