Biodegradable Heparin‐Loaded Microspheres: Carrier Molecular Composition and Microsphere Structure

Abstract

Microspheres of amphiphilic triblock polymers PLLA-PEG-PLLA were investigated as carriers for heparin delivery. Two series of PLLA-PEG-PLLA triblock were synthesized and prepared into microspheres with heparin loaded. The microspheres were hollow and the surface morphology varied from smooth to porous. The pore size increased with increasing PEG content. The microsphere size distribution showed that higher PEG content increased the average microsphere size. The release rate of heparin was closely related to the surface morphology of the microspheres. DSC spectra showed that both cold crystalline temperature (Tc) and crystalline melting temperature (Tm) of heparin-loaded microspheres were related to the copolymer composition and the Tc was lower than those of corresponding pure microspheres. [IMAGES: SEE TEXT]

Reverse micelles prepared from amphiphilic polylactide- b -poly(ethylene glycol) block copolymers for controlled release of hydrophilic drugs

“…7), in agreement with literature (Luo et al, 2006). Upon immersion in PBS, the membrane might be hydrated and swollen, thus the active ingredient heparin could diffuse through the opening pores out of the membrane.…”

Fabrication of drug‐loaded electrospun aligned fibrous threads for suture applications

“…In addition, the curves also show that the T m of PLLA in the core‐shell fibers was at a range of 146–148°C which is remarkably lower than that in the single component fibers. This result can be ascribed to the fact that the molecular chains of polymer become smoother and easy to move by adding small molecule drug into electrospun fibers, a similar result can be found in the case of heparin‐loaded polymer microspheres 61…”

“…This result can be ascribed to the fact that the molecular chains of polymer become smoother and easy to move by adding small molecule drug into electrospun fibers, a similar result can be found in the case of heparin-loaded polymer microspheres. 61 Figure 13 shows XRD patterns of the PLLA bulk resin and the various electrospun fibers. The asreceived PLLA exhibited two main diffraction peaks at 16.28 and 22.88 and a small peak at 24.88.…”

Control of morphology and structure of calcium carbonate crystals by heparin

“…Clinically, use of a HEP microcarrier will remarkably improve the bio-availability of HEP. Luo et al reported a kind of biodegradable HEP microcarrier with the EE of HEP less than 16.7% [28]. We recently described a HEP microcarrier prepared via layer-by layer self-assembly technique with 74.4% of EE [29].…”