[Preparation and property study of doxorubicin loaded microspheres].

OBJECTIVE: To prepare doxorubicin-loaded polyvinylalcohol-acrylic acid (PVA-AA) microspheres and evaluate properties of this chemoembolic agent. METHODS: PVA-AA microspheres were synthesized by inverse suspension polymerization method and then verified by infrared spectroscopy. drug loading (DL) and entrapment efficiency (EE%) were measured after doxorubicinwas loaded on PVA-AA microspheres. Their morphology and elasticity were investigated by optical microscope, environmental scanning electron microscope and texture analyzer, respectively. T-cell apparatus was used to evaluate the in vitro release behavior of doxorubicin-loaded microspheres.The external carotid of the rabbit was chosen as an embolization site to evaluate the in vivo embolic property of the microspheres. RESULTS: PVA-AA microspheres, which were transparent spheres,turned into red spheres after doxorubicin loading. DL of the microspheres was (20.56 ± 0.69)g/L and (23.25 ± 0.27) g/L,and EE% was 82.22% ± 2.76% and 93.00% ± 1.06% within 20 min and 6 h, respectively. The in vitro release results showed a significantly delayed release of the drug for 10.32% ± 0.47% after 24 h. The Young's modulus was (178.30 ± 12.33) kPa and (213.29 ± 15.61) kPa for blank microspheres and doxorubicin-loaded microspheres, respectively. Both blank microspheres and doxorubicin-loaded microspheres exhibited good elasticity. In vivo embolization showed that 0.3 mL of microspheres could produce distal embolic efficiency. CONCLUSION: The doxorubicin-loaded microspheres are expected to be a promising new chemoembolic agent.

Poly(acrylic acid) microspheres loaded with lidocaine: preparation and characterization for arterial embolization.

A new embolic agent, poly(acrylic acid) microspheres (PMs), was synthesized and the cytocompatibility was proved by mouse L929 fibroblast cells. An analgesic drug, lidocaine, was loaded on the PMs to relief pain caused by embolization. PMs and lidocaine loaded microspheres (LMs) were characterized by investigating infrared spectrum, morphology, particle size, and equilibrium water contents (EWC). A series of tests were employed to evaluate the elasticity of PMs, LMs and Embosphere™, including once compression, twice compression, and stress relaxation test. The pressures of PMs and LMs passing through a catheter were measured on line by our new designed device. Drug release was studied with T-cell apparatus. The properties of PMs and LMs were proved to be suitable for embolization. Both PMs and LMs in this study might be potential embolic agents in the future.