Biodegradable Hydrophobic Injectable Polymers for Drug Delivery and Regenerative Medicine

Abstract

Biodegradable, hydrophobic, and injectable liquid polymers are capable of achieving the minimally invasive, sustained, and local release of drugs. These hydrophobic injectable polymers also have potential in the area of regenerative medicine where the biomaterial should be stable for a certain period and then degrade to allow the growth of cells/tissues. This review presents exclusive coverage of biocompatible hydrophobic injectable pasty or liquid polymers that can be injected without the use of any solvent for drug delivery, tissue augmentation, and regenerative medicine application. The synthesis methodologies of several major types of hydrophobic pasty polymers used in the biomedical fields and their properties with the foremost criteria to serve as injectable biomaterial for localized drug delivery and regenerative medicine is described. The hydrophobic biodegradable injectable polymers discussed are aliphatic polyesters, polycarbonates and polyanhydrides, prepared from: lactic acid, glycolic acid, caprolactone, aliphatic diols and diacids, hydroxy fatty acids, and triglycerides such as castor oil.

Current Perspectives on Synthetic Compartments for Biomedical Applications

“…For any biologically relevant material, the transition from the research laboratory to a clinical setting is a complex procedure. This is particularly true when the final application is in the field of medicine, pharmaceutical production, or personal care [ 130 , 131 , 132 ]. In the case of compartments, there is a complex set of requirements, first for the copolymers used to generate the compartments and then for the compartments themselves.…”

Synthesis of Aliphatic Polyanhydrides with Controllable and Reproducible Molecular Weight

“…Polyanhydrides have been widely explored as biodegradable polymers for the last four decades [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 ]. In 1909, Bucher and Slade first synthesized polyanhydrides upon heating isophthalic acid and terephthalic acid in presence of acetic anhydride [ 1 ].…”

“…In 1983, Langer used polyanhydrides for the first time as biodegradable carriers in various medical devices by identifying and accomplishing the hydrolytic instability of polyanhydrides for controlled drug delivery applications [ 1 ]. Polyanhydrides degrade under a wide range of physiological conditions that enable controlled release throughout the degradation process [ 3 , 4 , 5 ].…”

“…Polyanhydrides in the form of slabs, films, rods, microspheres and nanospheres, have been used as therapeutic delivery devices [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 ]. Gliadel wafers are in clinical use for the delivery of carmustine (bis-chloroethylnitrosourea, BCNU) for the treatment of brain cancer.…”

“…Polyanhydrides used in other drug delivery applications include local anesthetics, anticancer agents, anticoagulants, delivery of DNA in gene therapy and other large molecules such as proteins, and delivery of neuroactive drugs. The drug delivery of polyanhydrides has been reviewed [ 4 , 5 ].…”