240 Anti-Inflammatory & Anti-Allergy Agents in Medicinal Chemistry, 2008, 7, 240-251 1871-5230/08 $55.00+.00 © 2008 Bentham Science Publishers Ltd. Biodegradable Polymer Based Particulate Carrier(s) for the Delivery of Proteins and Peptides Neeraj Mishra 1 , Amit K. Goyal 1 , Kapil Khatri 1 , Bhuvaneshwar Vaidya 1 , Rishi Paliwal 1 , Shivani Rai 1 , Abhinav Mehta 1 , Shailja Tiwari 1 , Shiva Vyas 2 and Suresh P. Vyas* 1 Drug Delivery Research Laboratory, Department of Pharmaceutical Sciences, Dr. H. S. Gour viswavidyalaya, Sagar (M.P.); 2 School of Biotechnology, Devi Ahilya Vishwavidyalaya, Indore (M.P.), India Abstract: Construction of safe and effective delivery systems for proteins and peptides is demand of current clinical prac- tices. Biodegradable polymers based particulates carriers fulfill much of the requirement in this applicable field. Number of marketed products related to biodegradable polymers encapsulating proteins is increasing. However, it has not achieved its proper place since problems related to the protein processing and stabilization limits the scientific community. In this present review we have summarized various aspects related to the formulation and processing of biodegradable polymer- ized microparticles/ nanoparticles for delivery of therapeutic proteins and peptides. A brief introduction of biodegradable polymers has been incorporated for reader’s benefit. In addition, biodegradable polymers based carriers designed for vac- cine delivery has been incorporated in detail. Functionalized biodegradable carrier(s) for site specific delivery of proteine- ous matter has also been discussed. Keywords: Biodegradable polymers, protein, peptide, vaccine, microparticles, nanoparticles, lectins, poloxamer, PEGylation. INTRODUCTION The demand and role of proteins and peptide specially designed for pharmacotherapeutics purpose is increasing in clinical practice to solve many of the current untreatable diseases. The research progress in the field of biotechnology regularly increases number of clinically useful proteins and peptides for this purpose. Proteins are large molecular weight polypeptides which are susceptible to proteolysis, chemical modification, and denaturation during storage and admini- stration. Thus, controlled and targeted delivery is prerequi- site to stabilize and utilize the maximum benefit of these agents. A large number of the carriers have been designed for delivery of proteins and peptides via liposome, niosome, polymeric nanoparticles, solid lipid nanoparticles etc. Poly- mer based carriers have taken much attention of the scientific community for safe and effective delivery of proteins. In developing countries, environmental pollution by syn- thetic polymers has assumed dangerous proportions. As a result, attempts have been made to solve these problems in- cluding biodegradability into polymers in everyday use through slight modifications of their structures. Biodegrad- able polymers are the youngest members of the materials family with increasing applications in pharmaceutical, medi- cal and biomedical engineering [1-5]. Biodegradable poly- mers are not limited to release of drugs, peptides or proteins at the characteristic rates and to specific target site, but are also extended to medical devices [6] and wound dressing [7] *Address correspondence to this author at the Drug Delivery Research Laboratory, Department of Pharmaceutical Sciences, Dr. H. S. Gour Vish- wavidyalaya, Sagar (M.P.), India; Tel: +91-7582-265525; Fax: +91-7582- 265525; E-mail: vyas_sp@rediffmail.com, spvyas@bsnl.in as well as for fabricating scaffold in tissue engineering [8,9]. To meet these demands, biodegradable block copolymers have been found as promising biomaterials by virtue of their ability to manipulate their amphiphilic behavior, technical and physical properties by adjusting the ratio of the constitut- ing block or adding new blocks of desired properties. The recent developments in this field are the subject of this re- view, which addresses the types of biodegradable block co- polymers, synthetic routes, properties and their uses as dif- ferent carriers for delivery of various drugs, peptide and pro- teins, as targeted agents for site specific delivery. BIODEGRADABLE POLYMERS Biodegradation is a natural process by which organic chemicals in the environment are converted to simpler com- pounds, mineralized and redistributed through elemental cycles such as the carbon, nitrogen and sulphur cycles. Bio- degradation can only occur within the biosphere as microor- ganisms play a central role in the biodegradation process. Some microorganisms and enzymes capable of degrading them have also been identified. Biodegradable polymers are having many advantages as effective/specific delivery carri- ers for proteins and peptides. Some of the advantages and limitations are enlisted in Fig. (1). Biodegradable polymers can be either natural or synthetic. The natural materials in- clude polysaccharides (starch, alginate, chitin/chitosan, and hyaluronic acid derivatives), proteins (soy, collagen, fibrin gels, silk) and a variety of biofibers such as lignocellulosic natural fibers used for reinforcement, which are described in detailed and reviews elsewhere [10-14]. Commonly used biodegradable polymers, along with their selected physical and chemical characteristics, are listed in Table 1.