Functionalized Keratin as Nanotechnology-Based Drug Delivery System for the Pharmacological Treatment of Osteosarcoma

Abstract

Osteosarcoma therapy might be moving toward nanotechnology-based drug delivery systems to reduce the cytotoxicity of antineoplastic drugs and improve their pharmacokinetics. In this paper, we present, for the first time, an extensive chemical and in vitro characterization of dual-loaded photo- and chemo-active keratin nanoparticles as a novel drug delivery system to treat osteosarcoma. The nanoparticles are prepared from high molecular weight and hydrosoluble keratin, suitably functionalized with the photosensitizer Chlorin-e6 (Ce6) and then loaded with the chemotherapeutic drug Paclitaxel (PTX). This multi-modal PTX-Ce6@Ker nanoformulation is prepared by both drug-induced aggregation and desolvation methods, and a comprehensive physicochemical characterization is performed. PTX-Ce6@Ker efficacy is tested on osteosarcoma tumor cell lines, including chemo-resistant cells, using 2D and 3D model systems. The single and combined contributions of PTX and Ce6 is evaluated, and results show that PTX retains its activity while being vehiculated through keratin. Moreover, PTX and Ce6 act in an additive manner, demonstrating that the combination of the cytostatic blockage of PTX and the oxidative damage of ROS upon light irradiation have a far superior effect compared to singularly administered PTX or Ce6. Our findings provide the proof of principle for the development of a novel, nanotechnology-based drug delivery system for the treatment of osteosarcoma.

Adjuvant Biophysical Therapies in Osteosarcoma

“…Kusuzaki et al showed that AO-PDT has a strong cytocidal effect, not only on chemosensitive mouse OS cells, but also on MDR mouse OS cells [157]. This effects on MDR were confirmed by Martella et al [158] in vitro study demonstrating that the combination of PTX-Ce6@Ker (paclitaxel loaded in keratine nanoparticles functionalized with the photosensitizer Chlorin-e6) and PDT was highly effective on MDR Saos2 cells. A recent interesting application of PDT is its combination with doxorubicin engineered osteogenic scaffold that would allow to act simultaneously destroying the tumor by increasing the temperature and the release of doxorubicin (after laser stimulation), and promoting bone regeneration thanks to the osteoinductive characteristics of the scaffold [159,160].…”

Recent trends in protein and peptide-based biomaterials for advanced drug delivery

“…Due to its exquisite and versatile loading capacity, keratin has also been harnessed to create bimodal nanoformulations that combine chemotherapeutics and photodynamic therapy. Martella et al functionalized high molecular weight keratin with the photosensitizer Chlorin-e6 (Ce6) and induced spontaneous nanoparticle formation by mixing the protein with paclitaxel, a chemotherapeutic that aggregates with the hydrophobic residues in keratin [ 108 ]. This is an attractive bottom-up nanoparticle fabrication strategy, as it did not require any toxic crosslinkers or downstream purification steps for nanoparticle fabrication.…”

“…Although Ce6 typically experiences a drop in fluorescence in acidic conditions, the keratin protected the photosensitizer and no decrease in fluorescence was observed. Further, the nanoparticle formulation transported the paclitaxel in a three-dimensional tumor model system without reducing the drug's potency [ 108 ]. Keratin nanoparticles have also been engineered for mucoadhesive drug delivery.…”

<p>MicroRNA-584 Impairs Cellular Proliferation and Sensitizes Osteosarcoma Cells to Cisplatin and Taxanes by Targeting CCN2</p>

“…3 Among numerous antitumor agents, taxanes is widely applied for treating breast and pancreatic cancers, and the efficacy of taxanes for treating OS was previously revealed to be a great success in high-grade OS and recurrent or metastatic soft-tissue sarcomas. 4 However, increasing chemoresistance was saw in a great number of OS patients in the past few years, therefore the study of the underlying mechanisms regarding the chemosensitivity of OS cells is of great importance to enhance the survival rate. 5 The dysregulation of microRNAs (miRNAs), small noncoding RNAs, have been observed in many human pathologies, and most prominently, in carcinogenesis.…”