Drug Delivery & Advanced Materials Team, School of Pharmacy & Biomolecular Sciences, RCSI, Dublin, Ireland and Tissue Engineering Research Group, Department of Anatomy & Regenerative Medicine, RCSI, Dublin, Ireland and Trinity Centre for Biomedical Engineering, Trinity College Dublin (TCD), Dublin, Ireland and SFI Advanced Materials and Bioengineering Research (AMBER) Centre, RCSI & TCD, Ireland.
Tissue Engineering Research Group, Department of Anatomy & Regenerative Medicine, RCSI, Dublin, Ireland and Trinity Centre for Biomedical Engineering, Trinity College Dublin (TCD), Dublin, Ireland and SFI Advanced Materials and Bioengineering Research (AMBER) Centre, RCSI & TCD, Ireland.
Biomater Sci. 2021 Jul 13;9(14):4984-4999. doi: 10.1039/d1bm00094b.
Increasingly, tissue engineering strategies such as the use of biomaterial scaffolds augmented with specific biological cues are being investigated to accelerate the regenerative process. For example, significant clinical challenges still exist in efficiently healing large bone defects which are above a critical size. Herein, we describe a cell-free, biocompatible and bioresorbable scaffold incorporating a novel star-polypeptide biomaterial as a gene vector. This gene-loaded scaffold can accelerate bone tissue repair in vivo in comparison to a scaffold alone at just four weeks post implantation in a critical sized bone defect. This is achieved via the in situ transfection of autologous host cells which migrate into the implanted collagen-based scaffold via gene-loaded, star-shaped poly(l-lysine) polypeptides (star-PLLs). In vitro, we demonstrate that star-PLL nanomaterials designed with 64 short poly(l-lysine) arms can be used to functionalise a range of collagen based scaffolds with a dual therapeutic cargo (pDual) of the bone-morphogenetic protein-2 plasmid (pBMP-2) and vascular endothelial growth factor plasmid (pVEGF). The versatility of this polymeric vector is highlighted in its ability to transfect Mesenchymal Stem Cells (MSCs) with both osteogenic and angiogenic transgenes in a 3D environment from a range of scaffolds with various macromolecular compositions. In vivo, we demonstrate that a bone-mimetic, collagen-hydroxyapatite scaffold functionalized with star-PLLs containing either 32- or 64- poly(l-lysine) arms can be used to successfully deliver this pDual cargo to autologous host cells. At the very early timepoint of just 4 weeks, we demonstrate the 64-star-PLL-pDual functionalised scaffold as a particularly efficient platform to accelerate bone tissue regeneration, with a 6-fold increase in new bone formation compared to a scaffold alone. Overall, this article describes for the first time the incorporation of novel star-polypeptide biomaterials carrying two therapeutic genes into a cell free scaffold which supports accelerated bone tissue formation in vivo.
越来越多的组织工程策略，例如使用生物材料支架并加入特定的生物学线索，正在被研究以加速再生过程。例如，在有效地治疗大于临界尺寸的大骨缺损方面仍然存在显著的临床挑战。在这里，我们描述了一种无细胞、生物相容和可生物吸收的支架，其中包含一种新型星状多肽生物材料作为基因载体。与单独的支架相比，这种负载基因的支架可以在植入临界尺寸骨缺损后的四周内，加速体内骨组织的修复。这是通过负载基因的星型聚赖氨酸多肽（星型-PLL）将自体宿主细胞原位转染到植入的胶原基支架中实现的。在体外，我们证明了设计有 64 个短聚赖氨酸臂的星型-PLL 纳米材料可用于用双治疗有效负载（pDual）的骨形态发生蛋白-2 质粒（pBMP-2）和血管内皮生长因子质粒（pVEGF）对一系列胶原基支架进行功能化。这种聚合物载体的多功能性突出表现在其能够在 3D 环境中从具有各种高分子组成的各种支架转染间充质干细胞（MSCs），并带有成骨和血管生成的转基因。在体内，我们证明了具有星型-PLL 功能化的仿生骨-胶原-羟基磷灰石支架，其中包含 32-或 64-聚赖氨酸臂，可用于成功地将这种 pDual 有效负载递送到自体宿主细胞。在仅仅 4 周的非常早期时间点，我们证明了 64 星-PLL-pDual 功能化支架作为一种特别有效的平台，可以加速骨组织再生，与单独的支架相比，新骨形成增加了 6 倍。总的来说，本文首次描述了将两种治疗基因的新型星状多肽生物材料纳入无细胞支架中，该支架支持体内加速骨组织形成。
