Gene therapy is an emerging field in which nucleic acids are used to control protein expression. The necessity of delivering nucleic acids to specific cell types and intracellular sites demands the use of highly specialized gene carriers. As a carrier modification technique, mineralization has been successfully used to modify viral and non-viral carriers, providing new properties that ultimately aim to increase the transfection efficiency. However, for the specific case of polyplexes used in gene therapy, recent literature shows that interaction with calcium, a fundamental step of mineralization, might be effective to increase transfection efficiency, leaving an ambiguity about of the role of mineralization for this type of gene carriers. To answer this question and to reveal the properties responsible for increasing transfection efficiency, we mineralized poly(aspartic acid) coated polyplexes at various CaCl₂ and Na₃PO₄ concentrations, and evaluated the resultant carriers for physicochemical and morphological characteristics, as well as transfection and delivery efficiency with MC3T3-E1 mouse osteoblastic cells. We found that both mineralization and calcium incubation positively affected the transfection efficiency and uptake of polyplexes in MC3T3-E1 cells. However, this effect originated from the properties achieved by polyplexes after the calcium incubation step that are maintained after mineralization, including particle size increase, improved pDNA binding, and adjustment of zeta potential. Considering that mineralization can be a longer process than calcium incubation, we find that calcium incubation might be sufficient and preferred if improved transfection efficiency in vitro is the only effect desired.

基因治疗是一个新兴领域，其中使用核酸来控制蛋白质表达。将核酸递送到特定细胞类型和细胞内位点的必要性要求使用高度特化的基因载体。作为一种载体修饰技术，矿化已成功用于修饰病毒和非病毒载体，提供最终旨在提高转染效率的新特性。然而，对于基因治疗中使用的复合物的具体情况，最近的文献表明，与钙的相互作用（矿化的一个基本步骤）可能有效提高转染效率，从而使此类基因载体的矿化作用模糊不清。 . 为了回答这个问题并揭示负责提高转染效率的特性，₂和 Na ₃ PO ₄浓度，并评估所得载体的理化和形态特征，以及 MC3T3-E1 小鼠成骨细胞的转染和递送效率。我们发现矿化和钙孵育都对转染效率和 MC3T3-E1 细胞中复合物的摄取产生积极影响。然而，这种效果源于钙孵育步骤后复合物获得的特性，这些特性在矿化后保持，包括粒径增加、pDNA 结合的改善和 zeta 电位的调整。考虑到矿化可能是一个比钙孵育更长的过程，我们发现如果提高体外转染效率是唯一需要的效果，钙孵育可能就足够了，并且是首选。