PepGel, a self-assembling peptide nanofiber hydrogel, effectively controlled the release rate of BSA-linked cisplatin and could be injected via syringe, with cell culture confirming anti-cancer activity matched drug release kinetics.
Tunable release + injectable via syringePepGel's shear-thinning properties allow syringe injection, after which it reforms and slowly releases cisplatin at a rate controlled by gel concentration — combining clinical practicality with controlled drug delivery.
What the researchers found
PepGel (h9e peptide) formed a hydrogel triggered by BSA-linked cisplatin (BSA-CP), with BSA-CP serving dual roles as gelation trigger and drug payload. Fluorescence studies showed strong interaction between PepGel and BSA's hydrophobic subdomain. TEM and confocal microscopy confirmed BSA-CP dispersal within PepGel nanofibers with enhanced fiber aggregation. PepGel effectively inhibited BSA-CP diffusion even at concentrations below 0.3 wt%. Drug release rate was controllable by adjusting PepGel concentration. HeLa cell viability data was consistent with drug release kinetics, confirming maintained anti-cancer activity.
Why it matters
Local, sustained delivery of chemotherapy could reduce the severe systemic side effects that make cisplatin treatment so difficult for patients. An injectable peptide gel that can be administered through a syringe and slowly releases drug at the tumor site is a practical approach. The ability to tune release rate by adjusting gel concentration gives clinicians control over drug delivery kinetics.
How the study worked
PepGel concentration was varied to study effects on BSA-CP release kinetics. Fluorescence spectroscopy assessed PepGel-BSA interactions (tryptophan quenching). TEM and fluorescence confocal microscopy visualized drug distribution within nanofiber networks. UV spectroscopy measured BSA-CP release rates at different PepGel concentrations. HeLa cell culture assessed cytotoxicity correlating with drug release data.
What this study cannot tell us
In vitro study only — no animal tumor models were used. BSA-linked cisplatin may behave differently from clinical cisplatin formulations. Only HeLa cells were tested, limiting generalizability to different tumor types. The study didn't assess gel stability, degradation, or drug release in physiological conditions with enzymes. Long-term biocompatibility and immunogenicity of the peptide gel in vivo were not evaluated. The release kinetics were measured in simple buffer, not in tissue-like environments.
How to read the evidence
This is an in vitro biomaterials characterization study with comprehensive physical and biological assessment. The methodology is thorough for a materials development paper, including structural, spectroscopic, and cell viability analyses. However, no in vivo data exists.
When this study was published
Published in 2017, this study contributed to the then-emerging field of self-assembling peptide hydrogels for drug delivery. The technology has continued to develop with newer peptide designs and more sophisticated release mechanisms.
The bigger picture
Injectable peptide hydrogels represent a growing class of drug delivery materials that combine biocompatibility, biodegradability, and practical advantages (syringe-injectable, self-healing). This study demonstrates the concept using cisplatin, but the platform could potentially deliver any protein-bound drug. As cancer treatment moves toward local therapies and combination approaches, injectable peptide gels could fill an important niche between systemic chemotherapy and surgical implants.
Questions still open
- Does PepGel maintain controlled cisplatin release in the complex tissue environment of a solid tumor?
- How long does the hydrogel persist at an injection site before degrading, and does degradation affect drug release?
- Could this system be used for local delivery of other chemotherapy drugs or immunotherapy agents?
Common questions
How does a peptide gel deliver cancer drugs?
Why deliver chemotherapy locally instead of systemically?
Read the original research
Controlled release of BSA-linked cisplatin through a PepGel self-assembling peptide nanofiber hydrogel scaffold.
Amino acids, 49(12), 2015-2021
Citation
Liang, Jun; Liu, Gang; Wang, Jing; Sun, Xiuzhi Susan. (2017). Controlled release of BSA-linked cisplatin through a PepGel self-assembling peptide nanofiber hydrogel scaffold.. Amino acids, 49(12), 2015-2021. https://doi.org/10.1007/s00726-017-2444-z