In-chain functionalization through the combination of ring opening copolymerization and oxime “Click” reaction towards X-ray opaque polylactide copolymers

Recent Advances and Challenges in Barbier Polymerization

The Barbier reaction, a classical name reaction for carbon-carbon bond formation, has played important roles in organic chemistry for over 120 years. The introduction of the Barbier reaction into polymer chemistry for the development of a novel Barbier polymerization, expands the methodology, monomer, chemical structure and property libraries of polymerization, aggregation-induced emission (AIE) and non-traditional intrinsic luminescence (NTIL). This mini review focuses on Barbier polymerization, including the brief introduction of the history and importance of polymerization methods design and the achievements of Barbier polymerization from molecular design strategies, functionalities and properties. An outlook of Barbier polymerization is also proposed. This mini review on Barbier polymerization therefore may cause inspirations to scientists in different fields.

Development and evaluation of a novel biodegradable implants with excellent inflammatory response suppression effect by hot-melt extrusion

PURPOSE

Dexamethasone (Dex) is a widely used drug for the treatment of inflammatory and autoimmune conditions, however, long-term systemic use of Dex is associated with serious adverse effects. The objective of the present study was to develop an implantable device to avoid side effects and realize a controlled release of Dex at the implant site.

METHODS

Hydrophobic Dex was incorporated into biodegradable polyesters derived from PCL and Pluronic® L64 (PCL-Pluronic L64-PCL, PCLC) by hot-melt extrusion (HME) method to prepare Dex/PCLC implantable devices. Drug loading and encapsulation efficiency, a series of physicochemical properties, and in vivo features of the implants were studied.

RESULTS

The maximum value of the drug loading and encapsulation efficiency for the Dex/PCLC implants were up to 47% and 94%, respectively. Incorporation of Dex resulted in accelerated crystallization of PCLC, decreased the wettability, increased contact angles and viscosity, and accelerated Dex release rate and degradation rate from the implants in vivo. Moreover, Dex/PCLC implants showed excellent biocompatibility. Furthermore, the inflammatory response to the Dex/PCLC implants was less severe than that to the positive control group.

CONCLUSION

All these results suggested that Dex/PCLC implants might be a safe and controlled local drug delivery system with excellent inflammatory response suppression effect.