In situ preparation of glycoconjugate hollow microspheres mimics the extracellular matrix via interfacial polymerization

Chitin and chitosan composites for bone tissue regeneration

In the present world, where there is increased obesity and poor physical activity, the occurrence of bone disorders has also been increased steeply. Therefore, a significant progress has been made in organ transplantation, surgical reconstruction, and the use of artificial prostheses to treat the loss or failure of an organ or bone tissue in the recent years. Bone contains considerable amounts of minerals and proteins. The major component of bone is hydroxyapatite [Ca(10)(PO(4))(6)(OH)(2)] (60-65%) and is one of the most stable forms of calcium phosphate and it occurs along with other materials including collagen, chondroitin sulfate, keratin sulfate, and lipids. To remedy bone defects, new natural and synthetic materials are needed, which will have very similar properties as that of natural bone. Bone tissue engineering is a relatively new and emerging field, which paves the way for bone repair or regeneration. Polymers can serve as a matrix to support cell growth by having various properties such as biocompatibility, biodegradability, porosity, charge, mechanical strength, and hydrophobicity. Considerable attention has been given to chitin and chitosan composite materials and their applications in the field of bone tissue engineering in the recent years, which are natural biopolymers. This chapter reviews the various composites of chitin and chitosan, which are proved to be potential materials for bone tissue regeneration.

Injectable biomaterials for regenerating complex craniofacial tissues

Engineering complex tissues requires a precisely formulated combination of cells, spatiotemporally released bioactive factors, and a specialized scaffold support system. Injectable materials, particularly those delivered in aqueous solution, are considered ideal delivery vehicles for cells and bioactive factors and can also be delivered through minimally invasive methods and fill complex 3D shapes. In this review, we examine injectable materials that form scaffolds or networks capable of both replacing tissue function early after delivery and supporting tissue regeneration over a time period of weeks to months. The use of these materials for tissue engineering within the craniofacial complex is challenging but ideal as many highly specialized and functional tissues reside within a small volume in the craniofacial structures and the need for minimally invasive interventions is desirable due to aesthetic considerations. Current biomaterials and strategies used to treat craniofacial defects are examined, followed by a review of craniofacial tissue engineering, and finally an examination of current technologies used for injectable scaffold development and drug and cell delivery using these materials.