University of the Witwatersrand, Department of Pharmacy and Pharmacology, 7 York Road, Parktown, 2193, Johannesburg, South Africa.
Pharm Dev Technol. 2012 Jul-Aug;17(4):407-20. doi: 10.3109/10837450.2010.546406. Epub 2011 Jan 14.
This study aimed at elucidating an optimal synergistic polymer composite for achieving a desirable molecular bioadhesivity and Matrix Erosion of a bioactive-loaded Intravaginal Bioadhesive Polymeric Device (IBPD) employing Molecular Mechanic Simulations and Artificial Neural Networks (ANN). Fifteen lead caplet-shaped devices were formulated by direct compression with the model bioactives zidovudine and polystyrene sulfonate. The Matrix Erosion was analyzed in simulated vaginal fluid to assess the critical integrity. Blueprinting the molecular mechanics of bioadhesion between vaginal epithelial glycoprotein (EGP), mucin (MUC) and the IBPD were performed on HyperChem 8.0.8 software (MM+ and AMBER force fields) for the quantification and characterization of correlative molecular interactions during molecular bioadhesion. Results proved that the IBPD bioadhesivity was pivoted on the conformation, orientation, and poly(acrylic acid) (PAA) composition that interacted with EGP and MUC present on the vaginal epithelium due to heterogeneous surface residue distributions (free energy= -46.33 kcalmol(-1)). ANN sensitivity testing as a connectionist model enabled strategic polymer selection for developing an IBPD with an optimally prolonged Matrix Erosion and superior molecular bioadhesivity (ME = 1.21-7.68%; BHN = 2.687-4.981 N/mm(2)). Molecular modeling aptly supported the EGP-MUC-PAA molecular interaction at the vaginal epithelium confirming the role of PAA in bioadhesion of the IBPD once inserted into the posterior fornix of the vagina.
本研究旨在通过分子力学模拟和人工神经网络(ANN)阐明一种最佳协同聚合物复合材料,以实现载有生物活性的阴道内生物粘附聚合物装置(IBPD)的理想分子生物粘附性和基质侵蚀。采用直接压缩法制备了 15 个胶囊状模型装置,模型生物活性物质为齐多夫定和聚苯乙烯磺酸钠。在模拟阴道液中分析基质侵蚀,以评估临界完整性。在 HyperChem 8.0.8 软件(MM+和 AMBER 力场)上对阴道上皮糖蛋白(EGP)、粘蛋白(MUC)与 IBPD 之间的分子粘附的分子力学进行蓝图设计,以量化和描述分子生物粘附过程中的相关分子相互作用。结果证明,IBPD 的生物粘附性取决于构象、取向和与存在于阴道上皮的 EGP 和 MUC 相互作用的聚(丙烯酸)(PAA)组成,这是由于表面残基分布不均(自由能=-46.33 kcalmol(-1))。作为连接主义模型的 ANN 敏感性测试使我们能够进行战略聚合物选择,以开发具有最佳延长基质侵蚀和卓越分子生物粘附性的 IBPD(ME=1.21-7.68%;BHN=2.687-4.981 N/mm(2))。分子建模恰当地支持了 EGP-MUC-PAA 在阴道上皮的分子相互作用,证实了 PAA 在插入阴道后穹窿后 IBPD 生物粘附中的作用。