Feldman Dale
Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
Materials (Basel). 2021 Aug 14;14(16):4572. doi: 10.3390/ma14164572.
Both the chemistry and size of a material formed in vivo, or an implanted biomaterial, can alter the in vivo host response. Within the size range covered within this review, over 1 μm, chemistry is only important if the solid material is unstable and leeching small molecules. The macrophage activity and the resultant inflammatory response, however, are related to the size of the solid material. The premise of this review is that differences in size of the solid material, in different cases, can be the reason why there is some individual-to-individual variation in response. Specifically, the inflammatory response is enhanced when the size is between 1-50 μm. This will be looked at for three configurations: spherical particulate (silicone oil or gel from breast implants), elongated particulate (monosodium urate [MSU] crystals in gout or in kidney stones), and fibers (e.g., polyester used in fabric implants). These specific examples were selected because many still believe that the clinical outcome for each is controlled by the surface chemistry, when in fact it is the size. In each case, specific studies will be highlighted to either show a mechanism for creating different sizes and therefore a differential biological response (first three) or how changing the size and shape (diameter and spacing of fibers, in this example) can affect the response and can help explain the different responses to fabric implants found in vivo within the 1-50 μm size range. It was found that polyester fibers under 70 μm had a significant increase in macrophage response. Further, it was found that compounds found in synovial fluid could limit MSU crystal size. In addition, it was shown that plasma with low triglyceride levels emulsifies silicone oils to a greater extent than plasma with higher triglyceride levels. Therefore, in three cases it appears that differences in the inflammatory response between individuals and between different implants could be explained just by the size of the material formed or implanted.
体内形成的材料或植入的生物材料的化学性质和尺寸都可能改变体内宿主反应。在本综述涵盖的尺寸范围内，超过1μm时，只有当固体材料不稳定并释放小分子时，化学性质才重要。然而，巨噬细胞活性和由此产生的炎症反应与固体材料的尺寸有关。本综述的前提是，在不同情况下，固体材料尺寸的差异可能是个体反应存在差异的原因。具体而言，当尺寸在1 - 50μm之间时，炎症反应会增强。这将针对三种形态进行研究：球形颗粒（隆胸植入物中的硅油或凝胶）、细长颗粒（痛风或肾结石中的尿酸钠[MSU]晶体）和纤维（例如织物植入物中使用的聚酯）。选择这些具体例子是因为许多人仍然认为每种情况的临床结果由表面化学性质控制，而实际上是尺寸。在每种情况下，将重点介绍特定研究，以展示产生不同尺寸从而导致不同生物学反应的机制（前三种情况），或者改变尺寸和形状（在此例中为纤维的直径和间距）如何影响反应，并有助于解释在1 - 50μm尺寸范围内体内对织物植入物的不同反应。研究发现，70μm以下的聚酯纤维巨噬细胞反应显著增加。此外，还发现滑液中的化合物可限制MSU晶体尺寸。另外，研究表明，甘油三酯水平低的血浆比甘油三酯水平高的血浆更能乳化硅油。因此，在三种情况下，个体之间以及不同植入物之间炎症反应的差异似乎仅由形成或植入材料的尺寸来解释。
