Electrosprayable Levan-Coated Nanoclusters and Ultrasound-Responsive Drug Delivery for Cancer Therapy

In this study, we synthesized levan shell hydrophobic silica nanoclusters encapsulating doxorubicin (L-HSi-Dox) and evaluated their potential as ultrasound-responsive drug delivery systems for cancer treatment. L-HSi-Dox nanoclusters were successfully fabricated by integrating a hydrophobic silica nanoparticle-doxorubicin complex as the core and an amphiphilic levan carbohydrate polymer as the shell by using an electrospray technique. Characterization analyses confirmed the stability, size, and composition of the nanoclusters. In particular, the nanoclusters exhibited a controlled release of Dox under aqueous conditions, demonstrating their potential as efficient drug carriers. The levanic groups of the nanoclusters enhanced the targeted delivery of Dox to specific cancer cells. Furthermore, the synergism between the nanoclusters and ultrasound effectively reduced cell viability and induced cell death, particularly in the GLUT5-overexpressing MDA-MB-231 cells. In a tumor xenograft mouse model, treatment with the nanoclusters and ultrasound significantly reduced the tumor volume and weight without affecting the body weight. Collectively, these results highlight the potential of the L-HSi-Dox nanoclusters and ultrasound as promising drug delivery systems with an enhanced therapeutic efficacy for biomedical applications

Role of Pif97 in Nacre Biomineralization: In Vitro Characterization of Recombinant Pif97 as a Framework Protein for the Association of Organic–Inorganic Layers in Nacre

Nacre is the inner layer of the mollusc shell and provides exceptional toughness via its highly organized organic–inorganic composite structure. Pif is an organic matrix protein from the nacreous layer of the pearl oyster Pinctada fucata and exhibits regulatory behavior in nacre formation. Here, we investigated features of Pif97, the N-terminal of Pif, using a recombinant form of Pif97 produced in Escherichia coli. We observed that recombinant Pif97 was able to efficiently form a complex with calcium ions. Additionally, recombinant Pif97 showed both in vitro growth inhibition of thermodynamically stable calcite, stabilization of amorphous calcium carbonate, and exclusive binding affinity to metastable aragonite and chitin. These results imply the participation of Pif97 in the calcification of nacre including the association of the inorganic phase and polysaccharide template. We propose that recombinant Pif97 has inherent characteristics of the native form, which are significant for interrelating with organic matrix and inorganic calcium carbonate during nacre biomineralization