Reinvestigation of the ring-opening polymerization of ε-caprolactone with 1,8-diazacyclo[5.4.0]undec-7-ene organocatalyst in bulk

Tailored Polymersomes for Enhanced Oral Drug Delivery: pH-Sensitive Systems for Intestinal Delivery of Immunosuppressants

Ensuring precise drug release at target sites is crucial for effective treatment. Here, pH-responsive nanoparticles for oral administration of mycophenolate mofetil, an alternative therapy for patients with inflammatory bowel disease unresponsive to conventional treatments is developed. However, its oral administration presents challenges due to its low solubility in the small intestine and high solubility and absorption in the stomach. Therefore, this aim is to design a drug delivery system capable of maintaining drug solubility compared to the free drug while delaying absorption from the stomach to the intestine. Successful synthesis and assembly of a block copolymer incorporating a pH-responsive functional group is achieved. Dynamic light scattering indicated a significant change in hydrodynamic size when the pH exceeded 6.5, confirming successful incorporation of the pH-responsive group. Encapsulation and controlled release of mycophenolate mofetil are efficiently demonstrated, with 90% release observed at intestinal pH. In vitro cell culture studies confirmed biocompatibility, showing no toxicity or adverse effects on Caco-2 cells. In vivo oral rat studies indicated reduced drug absorption in the stomach and enhanced absorption in the small intestine with the developed formulation. This research presents a promising drug delivery system with potential applications in the treatment of inflammatory bowel disease.

Recent Advances in Polycaprolactones for Anticancer Drug Delivery

Poly(ε-Caprolactone)s are biodegradable and biocompatible polyesters that have gained considerable attention for drug delivery applications due to their slow degradation and ease of functionalization. One of the significant advantages of polycaprolactone is its ability to attach various functionalities to its backbone, which is commonly accomplished through ring-opening polymerization (ROP) of functionalized caprolactone monomer. In this review, we aim to summarize some of the most recent advances in polycaprolactones and their potential application in drug delivery. We will discuss different types of polycaprolactone-based drug delivery systems and their behavior in response to different stimuli, their ability to target specific locations, morphology, as well as their drug loading and release capabilities.

Phosphazene Functionalized Silsesquioxane-Based Porous Polymer as Thermally Stable and Reusable Catalyst for Bulk Ring-Opening Polymerization of ε-Caprolactone

The bulk ring-opening polymerization (ROP) of ε-caprolactone using phosphazene-containing porous polymeric material (HPCP) has been studied at high reaction temperatures (130-150 °C). HPCP in conjunction with benzyl alcohol as an initiator induced the living ROP of ε-caprolactone, affording polyesters with a controlled molecular weight up to 6000 g mol-1 and moderate polydispersity (Ð~1.5) under optimized conditions ([BnOH]/[CL] = 50; HPCP: 0.63 mM; 150 °C). Poly(ε-caprolactone)s with higher molecular weight (up to Mn = 14,000 g mol-1, Ð~1.9) were obtained at a lower temperature, at 130 °C. Due to its high thermal and chemical stability, HPCP can be reused for at least three consecutive cycles without a significant decrease in the catalyst efficiency. The tentative mechanism of the HPCP-catalyzed ROP of ε-caprolactone, the key stage of which consists of the activation of the initiator through the basic sites of the catalyst, was proposed.