# Silica Nanobottles Filled with Photo-cross-linked GelMA for the Sustained Release of Hydrophilic Biomacromolecules

## TL;DR

Scientists created silica nanobottles filled with a special gel to slowly release large, water-soluble molecules like proteins and enzymes for extended periods.

## Contribution

A novel hybrid delivery system combining silica nanobottles and photo-cross-linked gelatin methacryloyl for sustained release of hydrophilic biomacromolecules.

## Key findings

- The system enables sustained intracellular stability of payloads for up to 24 hours in A549 cells.
- The release half-life can be extended to several weeks depending on the payload type and molecular weight.
- Delivered nerve growth factor promotes neurite outgrowth from PC12 cells, maintaining structural and functional integrity.

## Abstract

Nanobottles have garnered attention as a class of advanced
carriers
for drug delivery, because of their advantages, such as convenient
loading, high capacity, and a well-defined wall for surface modification.
However, strategies to achieve sustained release of hydrophilic biomolecules
remain limited. Here, we report a hybrid delivery platform that integrates
silica nanobottles with photo-cross-linked gelatin methacryloyl for
the encapsulation and controlled release of proteins, enzymes, and
polysaccharides. Upon cross-linking, the payloads show enhanced intracellular
stability, with minimal release in A549 cells for up to 24 h. This
system also enables control over release kinetics, with the half-life
extendible to several weeks depending on the type and/or molecular
weight of the payload. Importantly, released biomacromolecules retain
structural and functional integrity, and delivery of nerve growth
factor promotes robust neurite outgrowth from PC12 cells. This hybrid
system provides a versatile and programmable platform for the long-term
delivery of diverse hydrophilic therapeutics.