Assembly of Protein-Based Hollow Spheres Encapsulating a Therapeutic Factor

Abstract

Neurotrophins, as important regulators of neural development, function, and survival, have a therapeutic potential to repair damaged neurons. However, a controlled delivery of therapeutic molecules to injured tissue remains one of the greatest challenges facing the translation of novel drug therapeutics field. This study presents the development of an innovative protein−protein delivery technology of nerve growth factor (NGF) by an electrostatically assembled protein-based (collagen) reservoir system that can be directly injected into the injury site and provide long-term release of the therapeutic. A protein-based biomimetic hollow reservoir system was fabricated using a template method. The capability of neurotrophins to localize in these reservoir systems was confirmed by confocal images of fluorescently labeled collagen and NGF. In addition, high loading efficiency of the reservoir system was proven using ELISA. By comparing release profile from microspheres with varying cross-linking, highly cross-linked collagen spheres were chosen as they have the slowest release rate. Finally, biological activity of released NGF was assessed using rat pheochromocytoma (PC12) cell line and primary rat dorsal root ganglion (DRG) cell bioassay where cell treatment with NGF-loaded reservoirs induced significant neuronal outgrowth, similar to that seen in NGF treated controls. Data presented here highlights the potential of a high capacity reservoir-growth factor technology as a promising therapeutic treatment for neuroregenerative applications and other neurodegenerative diseases.

Tackling Cell Transplantation Anoikis: An Injectable, Shape Memory Cryogel Microcarrier Platform Material for Stem Cell and Neuronal Cell Growth

“…Many spherical microparticles designed to deliver growth factors do so with an initial burst release, with the majority of the growth factor released over the first day or two . Indeed, poor release kinetics is still a hurdle for local growth factor delivery in the CNS .…”

“…When observing a thin section through the cross section of a cryogel microcarrier, the cells can typically be seen to be adherent to the outer edge of the sphere (Figure S2a,b, Supporting Information), as this would be the first region the cell would contact during spinner flask cultivation. PC12 cells were cultivated for a longer time period (7 d) as it was desired to see if they could produce neurites on the cryogel microcarriers in the presence of NGF, which typically take an extended time to form . Figure e,f shows CLSM images of PC12 cells grown in the presence of medium containing 500 ng mL −1 of NGF (nondifferentiated PC12 cells can be seen in Figure S4c,d in the Supporting Information).…”

PMHS-reduced fabrication of hollow Ag–SiO2 composite spheres with developed porosity

“…These outstanding chemical and physical properties allow them to have the potential applications in a wide range of fields, such as separation, catalysis, sensor design and drug delivery [1][2][3][4]. Therefore, considerable research efforts have been devoted to fabricating hollow spheres with desired functionality.…”

Enhanced bioavailability of nerve growth factor with phytantriol lipid-based crystalline nanoparticles in cochlea

“…Imaging was done using an inverted fluorescent microscope (Olympus IX81; Mason Technologies, Dublin, Ireland). 21 The level of neurite outgrowth was quantified by measuring the neurite length in three random images from triplicate experiments.…”