Tissue scaffolds functionalized with therapeutic elastin‐like biopolymer particles

Abstract

Tissue engineering scaffolds are intended to provide mechanical and biological support for cells to migrate, engraft and ultimately regenerate the tissue. Development of scaffolds with sustained delivery of growth factors and chemokines would enhance the therapeutic benefits, especially in wound healing. In this study, we incorporated our previously designed therapeutic particles, composed of fusion of elastin‐like peptides (ELPs) as the drug delivery platform to keratinocyte growth factor (KGF), into a tissue scaffold, alloderm. The results demonstrated that sustained KGF–ELP release was achieved and the bioactivity of the released therapeutic particles was shown via cell proliferation assay, as well as a mouse pouch model in vivo, where higher cellular infiltration and vascularization were observed in scaffolds functionalized with KGF–ELPs.

Combinatorial Use of Therapeutic ELP‐Based Micelle Particles in Tissue Engineering

“…Most of these platforms employ ELP sequences, which form aggregated particles above their transition temperature with diameters in 600–800 nm range. [ 15,5,7 ] ELP polymers composed of hydrophobic and hydrophilic chains have been shown to form micelle‐like particles with smaller particle size. [ 14 ] Such design allows for ordered display of potential fusion partners where nanoparticles decorated with a protein of interest can be achieved by fusing the therapeutic moiety to the hydrophilic chain of the ELP ( Figure A).…”

“…We have previously fused KGF to aggregated particle forming ELP sequences of similar length composed of 120 pentapeptide repeats, which formed particles with diameters above 600 nm. [ 15 ] Thus, the difference in ELP design resulted in a significant difference in particle size. Another feature to consider is the localization of the fusion partners on the ELP particles.…”

“…Protein Expression and Purification: All ELP proteins were expressed in 1 L of sterilized Terrific Broth cultures supplemented with 50 μg mL −1 kanamycin which were inoculated with 10 mL overnight culture as described previously. [15] The cells were incubated while shaking at 37 °C overnight, and protein expression was achieved through leaky expression provided by the T7 promoter of the pET24a plasmid. Cells were harvested by centrifugation at 5000 × g for 10 min and resuspended in 30 mL PBS per liter of culture.…”

“…Cell Proliferation Assay with A431 Cell Line in Response to Micelle-KGF: To evaluate the bioactivity of micelle-KGF, KGF responsive epithelial cell line A-431 was used in a cell proliferation assay as described previously. [15] A-431 cells were cultured in DMEM media supplemented with 10 % fetal bovine serum (FBS), 2 % l-glutamine, and 1 % penicillin-streptomycin in T-75 flasks until reaching confluency.…”

Application of Thermoresponsive Intrinsically Disordered Protein Polymers in Nanostructured and Microstructured Materials

“…ELP‐based biomaterials can be combined with commercially available grafts to improve therapeutic benefits. [ 168 ] ELP nanoparticles are also considered to be an ideal carrier for many hydrophobic drugs whose solubility limits their clinical effectiveness. [ 169 ] For example, Doxorubicin (Dox), a potent anticancer drug is plagued with issues of low solubility and severe toxic side effects such as myelosuppression, mucositis, and cardiac toxicity.…”