Zavan B, Vindigni V, Vezzù K, Zorzato G, Luni C, Abatangelo G, Elvassore N, Cortivo R
Department of Histology, University of Padova, Viale G. Colombo 3, 35131, Padova, Italy.
J Mater Sci Mater Med. 2009 Jan;20(1):235-47. doi: 10.1007/s10856-008-3566-3. Epub 2008 Aug 30.
The present study describes the production of hyaluronan based porous microparticles by a semi-continuous gas anti-solvent (GAS) precipitation process to be used as a growth factor delivery system for in vivo treatment of ulcers. Operative process conditions, such as pressure, nozzle diameter and HYAFF11 solution concentrations, were adjusted to optimize particle production in terms of morphology and size. Scanning electron microscopy (SEM) and light scattering demonstrated that porous nano-structured particles with a size of 300 and 900 nm had a high specific surface suitable for absorption of growth factors from the aqueous environment within the polymeric matrix. Water acted as a plasticizer, enhancing growth factor absorption. Water contents within the HYAFF11 matrix were analyzed by differential scanning calorimetry (DSC). The absorption process was developed using fluorescence dyes and growth factors. Immunohistochemical analysis confirmed the high efficiency of absorption of growth factor and a mathematical model was generated to quantify and qualify the in vitro kinetics of growth factor release within the polymeric matrix. In vivo experiments were performed with the aim to optimize timed and focal release of PDGF to promote optimal tissue repair and regeneration of full-thickness wounds.
本研究描述了通过半连续气体抗溶剂（GAS）沉淀法制备基于透明质酸的多孔微粒，用作生长因子递送系统以体内治疗溃疡。调整操作工艺条件，如压力、喷嘴直径和HYAFF11溶液浓度，以在形态和尺寸方面优化颗粒生产。扫描电子显微镜（SEM）和光散射表明，尺寸为300和900 nm的多孔纳米结构颗粒具有适合从聚合物基质内的水性环境中吸收生长因子的高比表面积。水作为增塑剂，增强了生长因子的吸收。通过差示扫描量热法（DSC）分析HYAFF11基质中的水分含量。使用荧光染料和生长因子开展吸收过程。免疫组织化学分析证实了生长因子的高吸收效率，并生成了一个数学模型来量化和表征聚合物基质内生长因子释放的体外动力学。进行体内实验的目的是优化血小板衍生生长因子（PDGF）的定时和局部释放，以促进全层伤口的最佳组织修复和再生。
