The first historical use of biomaterials dates to antiquity, when ancient Egyptians used sutures made from animal sinew.
Biomaterials may be natural or synthetic and are used in medical applications to support, enhance, or replace damaged tissue or a biological function. Grinstaff lab, Boston Universityīiomaterials play an integral role in medicine today-restoring function and facilitating healing for people after injury or disease. give rise to connective tissues (bone, cartilage, etc.Hydrogel sealants may allow pain-free dressing changes for patients with burns.There are two predominant lineages of stem cells:.Stem cells naturally exist in some tissues (especially those that rapidly proliferate or remodel) and are present in the circulation.can differentiate into functional cell types.tendency to either lose potency or de-differentiate with too many passages.
BIOMATERIALS IN TISSUE ENGINEERING PPT SERIAL
serial expansion of primary cells (can increase population by 100-1000X).
low cellular yield (can only harvest so much). differentiated cells harvested from the patient (tissue biopsy). Various classifications of cells used in tissue engineering applications:. Since the ultimate goal of tissue engineering is to develop replacement tissue (or organs) for individuals, the use of autologous cells would avoid any potential immunological complications. nutrients, amino acids, vitamins, minerals, growth factors, etc. pH, osmolality, ionic strength, buffering agents. culture (growth) media replenished periodically. ultra-violet light, 70% ethanol, steam autoclave, gamma irradiation, ethylene oxide gas. three-dimensional (scaffolds or templates). attachment of growth factors, binding sites for integrins, etc. must match degradation rate with tissue growth. calcium phosphate based for bone tissue engineering. also a mechanism by with cells respond to external stimuli (“mechanical transducers”). several specialized receptors that allow for cell-ECM interactions. since cells synthesize the ECM, they can modify the ECM to elicit specific cellular responses. ECM is multifunctional and also provides a substrate that cells can communicate. 1.5-2 nm diameter and only allow transport of small molecules ~1 kDa. other serve to create junctions between adjacent cells allowing for direct cytoplasmic communication. some membrane receptors are adhesive molecules. bind to membrane receptors usually with high affinity (low binding constants: 10-100 pM). growth factors, steroids, hormones, cytokines, chemokines. 
small proteins (15-20 kDa) which are chemically stable with long half-lives (unless specifically degraded). there can be as many as 7-10 distinct levels of structural organization in some tissues or organs. These structural levels exist from the macroscopic level (centimeter range) all the way down the molecular level (nanometer range). several levels of structural hierarchy”. Before a tissue can be developed in vitro, first we must understand how tissues are organized. Research is presently being conducted on several different types of tissues and organs, including:. Tissue Engineering is the in vitro development (growth) of tissues or organs to replace or support the function of defective or injured body parts.
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