Immobilization and controlled release of prostaglandin E₂ from poly‐L‐lactide‐co‐glycolide microspheres

Abstract

Prostaglandin E(2) (PGE(2)) is an arachidonic acid metabolite involved in physiological homeostasis and numerous pathophysiological conditions. Furthermore, it has been demonstrated that prostaglandins have a stimulating effect not only on angiogenesis in situ and in vitro but also on chondrocyte proliferation in vitro. Thus, PGE(2) represents an interesting signaling molecule for various tissue engineering strategies. However, under physiological conditions, PGE(2) has a half-life time of only 10 min, which limits its use in biomedical applications. In the present study, we investigated if the incorporation of PGE(2) into biodegradable poly-L-lactide-co-glycolide microspheres results in a prolonged release of this molecule in its active form. PGE(2)-modified microspheres were produced by a cosolvent emulsification method using CHCl(3) and HFIP as organic solvents and PVA as emulsifier. Thirteen identical batches were produced; and to each batch 1.0 mL of serum-free medium was added. The medium was removed at defined time points and then analyzed by gas chromatography tandem mass spectrometry (GC/MS/MS) to measure the residual PGE(2) content. In this study we demonstrated the prolonged release of PGE(2), showing a linear increase over the first 12 h, followed by a plateau and a slow decrease. The microspheres were further characterized by scanning electron microscopy.

Drug delivery from hydroxyapatite‐coated titanium surfaces using biodegradable particle carriers

“…We presume that this sustained release of DEX occurred through the PLGA polymer phase by controlled molecular diffusion because no significant surface changes were observed after 4 weeks of incubation 40. In a previous study, PLGA (lactide:glycolide = 85:15) particles were found to slowly degrade from within due to the formation of a superficial diffusion barrier and show nearly no superficial erosion even after 80 days in culture medium 41…”

High Resolution X-Ray Tomography - 3D Imaging for Tissue Engineering Applications

“…It is currently unknown if this porosity is due to local solvent-entrapment and accumulation, while the PLGA continuously hardens, forming hollow structures or, some other mechanism. This structural data might explain the release profile (Brochhausen et al, 2008), which is shown in Fig. 7b, showing a burst release early on with a plateau after 24 h and decreasing release afterwards.…”

Mass spectrometry in bioresorbable polymer development, degradation and drug‐release tracking

“…An HPLC/MS/MS method has been optimized to track the in vivo degradation of a zein porous scaffold . Recently, GC/MS was used to check the chemical structure of the enzymatic degradation products originated from PCL copolymers, and GC/MS/MS in drug release to measure the residual prostaglandin E2 (PGE2) content in biodegradable PLGA microspheres …”