In vitro degradation and release profiles for poly-dl-lactide-poly(ethylene glycol) microspheres containing human serum albumin

How to achieve sustained and complete protein release from PLGA-based microparticles?

“…Copolymers consisting of PLA and PEG, polylactide-co-poly(ethylene glycol) (PELA) have been designed with limited success (Zhou et al, 2003). Although they presented lower burst release, higher release rates, and the earlier onset for the second burst release for human serum albumin and glucose oxidase (GOD) loaded in PELA-microspheres, no complete release was reported and a loss of specific activity was detected for the released GOD after 7 days (67% of activity) (Li et al, 2000;Deng et al, 2001). Microspheres based on monomethoxypoly(oxyethylene)-poly(lactic acid) diblock copolymers (MPOE-PLA) did not avoid incomplete release either.…”

Investigation of endocytosis and cytotoxicity of poly-d, l-lactide-poly(ethylene glycol) micro/nano-particles in osteoblast cells

“…The level of significance was set at P , 0.05. 28 Our research group has previous experience with preparing nano-and micro-scaled particles. The average size of the particles can be controlled by adjusting the monomer ratio in copolymers' backbone and altering the parameters of preparation technology.…”

“…The average size of the particles can be controlled by adjusting the monomer ratio in copolymers' backbone and altering the parameters of preparation technology. 13,28 Here, based on our previous research, the particles with different average size were easily fabricated. Figure 1A displays the mean diameter and its polydispersity (Pdi) of the particles.…”

“…[25][26][27] In our research group PELA microspheres used as drug delivery systems have been widely studied, from the preparation method to the factors influencing the in vitro degradation profiles and in vitro drug release profiles. 13,28 However, the biological evaluation for PELA microspheres was rarely referred to in our previous report. In this paper, four kinds of microspheres based on biodegradable polymers such as PLA, and PELA with PEG content of 10%, 20%, or 30%, were prepared by a double emulsion-solvent evaporation technique to investigate cytotoxicity and phagocytosis.…”

Hydrocortisone release from tablets based on bioresorbable poly(ether-ester-urethane)s

“…This technology requires biodegradable polymers that are metabolized or excreted by the body as non-toxic compounds. Such systems offer numerous advantages compared to conventional dosage forms, including reduced dosing requirements, improved efficacy, and reduced toxicity (Deng et al, 1999;Deng et al, 2001;Park, Kim, Kim, 2005;Mohamadnia et al, 2009). Controlled release can be achieved by using various devices, for example mechanical pumps, osmotic pumps, diffusion-controlled systems containing reservoirs, or matrix systems, and chemically controlled systems composed of biodegradable or non-biodegradable polymers, among others (Park, Kim, Kim, 2005).…”