Scaffold: A Novel Carrier for Cell and Drug Delivery

Abstract

Scaffolds are implants or injects, which are used to deliver cells, drugs, and genes into the body. Different forms of polymeric scaffolds for cell/drug delivery are available: (1) a typical three-dimensional porous matrix, (2) a nanofibrous matrix, (3) a thermosensitive sol-gel transition hydrogel, and (4) a porous microsphere. A scaffold provides a suitable substrate for cell attachment, cell proliferation, differentiated function, and cell migration. Scaffold matrices can be used to achieve drug delivery with high loading and efficiency to specific sites. Biomaterials used for fabrication of scaffold may be natural polymers such as alginate, proteins, collagens, gelatin, fibrins, and albumin, or synthetic polymers such as polyvinyl alcohol and polyglycolide. Bioceramics such as hydroxyapatites and tricalcium phosphates also are used. Techniques used for fabrication of a scaffold include particulate leaching, freeze-drying, supercritical fluid technology, thermally induced phase separation, rapid prototyping, powder compaction, sol-gel, and melt moulding. These techniques allow the preparation of porous structures with regular porosity. Scaffold are used successfully in various fields of tissue engineering such as bone formation, periodontal regeneration, repair of nasal and auricular malformations, cartilage development, as artificial corneas, as heart valves, in tendon repair ,in ligament replacement, and in tumors. They also are used in joint pain inflammation, diabetes, heart disease, osteochondrogenesis, and wound dressings. Their application of late has extended to delivery of drugs and genetic materials, including plasmid DNA, at a controlled rate over a long period of time. In addition, the incorporation of drugs (i.e., inflammatory inhibitors and/or antibiotics) into scaffolds may be used to prevent infection after surgery and other disease for longer duration. Scaffold also can be used to provide adequate signals (e.g., through the use of adhesion peptides and growth factors) to the cells, to induce and maintain them in their desired differentiation stage, and to maintain their survival and growth. The present review gives a detailed account of the need for the development of scaffolds along with the materials used and techniques adopted to manufacture scaffolds for tissue engineering and for prolonged drug delivery.

Fabrication of tough poly(ethylene glycol)/collagen double network hydrogels for tissue engineering

“…The porous structure and tissue-like soft and wet properties of hydrogels have potential applications in the development of implantable drug reservoirs and cell scaffolds. [4][5][6][7] Moreover, hydrogels that are based on biomolecules, 8 such as proteins (e.g., collagen [Col] 9 and gelatin 10,11 ) and polysaccharides (e.g., hyaluronic acid 12,13 and chitosan 14,15 ), acquire not only excellent biocompatibility but also specific bioactivity from their building blocks. These features can artificially mimic the extracellular matrix (ECM) for cell growth and proliferation, 16 and are highly advantageous in tissue regenerative therapy.…”

Controlled release of simvastatin from biodegradable hydrogels promotes odontoblastic differentiation

“…A drug delivery system (DDS) represents a practically promising technology that can modify the biodistribution of drugs and consequently enhance efficacy. Therefore, there have been several investigations of drug delivery materials demonstrating their feasibility in drug therapy 13) . Some previous reports have shown that DDS technology is necessary to enhance the therapeutic efficacy of various drugs 9,14,15) .…”

Development, optimization and characterization of glycyrrhetinic acid–chitosan nanoparticles of atorvastatin for liver targeting

“…In brief, receptor-mediated targeting system is the one that functioned with ligands via chemical coupling or physical coating ways, reaching the desired sites by the special interaction between the ligands in the system and the receptors on the surface of the desired organ Goyal et al, 2014b). There are many receptors present on the surface of hepatic cells, and receptor that is specific to hepatic parenchymal cells is asialoglycoprotein receptors, which has the ability to recognize the galactosylated ligands, lactobionic acid ligand, asialofetuin ligands, soybean-derived steryl glucoside ligands and many more (Garg et al, 2012;Malik et al, 2014). Similarly, glycyrrhetinic acid (GA) receptors are mainly found on the sinusoidal surface of mammalian hepatocytes.…”