J Pharm Pharmacogn Res 2(Suppl. 1): S36, 2014
Special supplement with the abstract book of LATINFARMA 2013
CO 060: PEGYLATION: AN EFFECTIVE TOOL FOR BIOMASKING
Ramón JA1, Saez V1, Peniche C1, Hardy E2.
Nowadays, a large group of medical treatments are based on new substances. These were obtained due to strong development of science and technology in last few decades and include: (i) proteins and peptides used as replacement therapy and as inhibitors or regulators of the immune system, (ii) materials used in drug delivery systems like phospholipids and biodegradable polymers, and (iii) metals and their alloys, polymers, ceramics and composites of them used in various devices such as prostheses, stents, heart valves, etc.
Unfortunately the behaviour of these materials in the body is sometimes negative for the initial purpose. For example, proteins and peptides have low stability in vivo, a short half-life time and immunogenicity. Among the problems associated with other materials are: a) thrombus formation on artificial surfaces in contact with living tissues, b) damages to the tissues (e.g. vascular weakening produced by the liposomes) and c) recognition and elimination by the reticuloendothelial system of micro/nano-devices used as DDS like liposomes and biodegradable polymer microspheres.
In general, all these phenomena are due to unwanted interactions that occur at the interfaces between biodrugs or synthetic biomaterials and biological medium. Consequently, any agent that mediates this interaction, and become to this in a more “natural” fashion, promotes the acceptance by living organisms of these “foreign bodies”. An ideal substance for this mediation, it might be call “biomasking”, is the polyethylene glycol (PEG).
This presentation is about advantages of PEGylation (conjugation to PEG) for biomasking. PEGylation is a well-established technology used to transform proteins, peptides, small molecules and oligonucleotides into more potent drugs than their corresponding unmodified native molecules. Furthermore, PEGylated liposomes had received approval for improve the delivery of encapsulated drugs, such as the anticancer agent doxorubicin, and PEG-modified polymers (such as nhexadecylcyanoacrylate and PLGA) are studied extensively to obtain enhanced particulate delivery systems.