Biocompatibility of poly(d,l-lactic-co-hydroxymethyl glycolic acid) microspheres after subcutaneous and subcapsular renal injection

A Uniform Ultra-Small Microsphere/SAIB Hybrid Depot with Low Burst Release for Long-Term Continuous Drug Release

“…Inflammation followed by neovascularization, fibrous encapsulation and fibrosis could be observed at the depot/ tissue interface after the intramuscular injection of Ris-m-SAIB depot. The above tissue responses were similar to those caused by the polymers (PLA and PLGA) approved by the FDA (7,41). This result suggests that the Ris-m-SAIB depot exhibited good biocompatibility with the muscle tissues.…”

Release and pharmacokinetics of near-infrared labeled albumin from monodisperse poly(d,l-lactic-co-hydroxymethyl glycolic acid) microspheres after subcapsular renal injection

“…PLHMGA microspheres loaded with NIR-BSA showed a continuous weight loss and a decrease in weight average molecular weight (M w ) during the course of the 35-day incubation, suggesting degradation via bulk erosion [35,36]. The observed erosion rate is similar to the degradation of empty PLHMGA microspheres with same size and polymer composition [18]. The in vitro cumulative protein release from microspheres, determined both with the NIR imager and the BCA protein assay, was comparable for the two methods (Fig.…”

“…This technique has been recently studied for stem cells [15] and for drug eluting depots, i.e. hydrogels [16,17] and polymeric microspheres [18,19]. Dankers et al [16] showed good biocompatibility of supramolecular hydrogels, suitable for short-time boost release of proteins, and demonstrated that a therapeutic protein (bone morphogenic protein 7) released from such a depot reduced local fibrotic responses in kidneys from healthy rats.…”

“…The applied microspheres in this study were based on poly(D,L-lactic-co-hydroxymethyl glycolic acid) (PLHMGA), an aliphatic polyester with improved properties for protein delivery [20][21][22][23]. Recently, it was demonstrated that monodisperse PLHMGA microspheres have good biocompatibility after subcutaneous and subcapsular renal administration in rats [18]. Such monodisperse microspheres can be prepared by membrane emulsification method, in which uniform-sized droplets are formed after a primary W/O emulsion (containing protein and polymer solutions, respectively) is pressed through a membrane with uniformly sized pores [24,25].…”

Drug-loaded poly(d,l-lactide-co-glycolide) microspheres as treatment for allergic contact dermatitis in mice model

“…[13][14][15] Drug release behavior can be regulated by adjusting polymer type, polymer molecular weight, and microsphere size and morphology. Microspheres can be taken through many routes, such as oral administration, 16 intravenous injection, 17 subcutaneous injection, 18,19 and pulmonary inhalation. 20 Based on these advantages, microspheres may be a proper candidate as a therapy for allergic contact dermatitis while few related research has been reported.…”