We assessed the rate of release of a model nucleoside (adenosine, 5%, w/w) from nine different lactide-glycolide or lactide-caprolactone polymers. The polymer discs were eluted every second day with an artificial cerebrospinal fluid at the elution rate roughly approximating the brain extracellular fluid formation rate. Adenosine in eluate samples was assayed by HPLC. Three polymers exhibited a ...

............................................................................................ 27 Introduction ........................................................................................ 27 Results and Discussion ..................................................................... 31 Synthesis of a Functionalized Lactide Monomer ......................... 31 Copolymerization of L-Lac...

Two-, three- and four-arm, star-shaped poly(epsilon-caprolactone) and poly(D,L-lactide) homopolymers, and copolymers of epsilon-caprolactone with D,L-lactide were synthesized via ring-opening polymerization of cyclic esters in the presence of glycerol, penthaerythritol and poly(ethylene glycol) as initiators and stannous octoate as a catalyst. Thus obtained oligomers were successfully used in t...

background: innovative bioactive films incorporated with antimicrobial agents have been recently developed for food preservation. the aim of this study was to evaluate antibacterial activity of polylactic acid (pla) films incorporated with ziziphora clinopodioides essential oil (zeo) and ethanolic propolis extract (epe) against some common food-borne pathogens. methods: the volatile chemical co...

implantable contraceptive is likely to be a promising new option for fertility control, as we have entered the twenty-first century and the world’s population grows by one billion people in a single decade. the main objective of this study was to develop a subdermal implant for levonorgestrol (a synthetic progestin from 19-norandrostanes) using a high molecular weight biodegradable polymer , i....

The catalytic potential of tin(II)acetate, tin(IV)acetate, dibutyltin-bis-acetate and dioctyl tin-bis-acetate was compared based on polymerizations L-lactide conducted in bulk at 160 or 130°C. With SnAc2 low-Lac/Cat ratios (15/1–50/1) were studied linear chains having one acetate carboxyl end group almost free cyclics obtained. Higher monomer/catalyst lower temperatures favored formation cycles...

Abstract Polymerizations of l -lactide catalyzed either by neat SnCl 2 or + difunctional cocatalysts were conducted in bulk at 180, 160 and 140 °C with variation the Lac/Cat ratio time. With poly(L-lactide) having weight average molecular weights (uncorrected M w ’s) up to 190 000 g mol −1 obtained mainly consisting linear chains. Addition salicylic acid 1,1-bisphenol yielded a higher fraction ...

The first heterobimetallic lactide ROP catalysts based on two divalent metals outperform the homobimetallic analogues, attributed to increased Lewis acidity of Mg or Ca (monomer coordination) and enhanced polarity Zn–Et/OR (propagation).