Related Experiment Video
Updated: Jul 9, 2026
The Synthesis of RGD-functionalized Hydrogels as a Tool for Therapeutic Applications
Published on: October 7, 2016
LysSYL-Loaded pH-Switchable Self-Assembling Peptide Hydrogels Promote Methicillin-Resistant Staphylococcus Aureus
He Liu1, Xuemei Wei2, Huagang Peng1
1Department of Microbiology, College of Basic Medical Sciences, Army Medical University, Key Laboratory of Microbial Engineering under the Educational Committee in Chongqing, Chongqing, 400038, China.
Abstract:
Staphylococcus aureus (S. aureus), especially methicillin-resistant S. aureus (MRSA), causes wound infections, whose treatment remains a clinical challenge. Bacterium-infected wounds often create acidic niches with a pH 4.5-6.5. Endolysin LysSYL, which is derived from phage SYL, shows promise as an antistaphylococcal agent. However, endolysins generally exhibit instability and possess low bioavailability in acidic microenvironments. Here, an array of self-assembling peptides is designed, and peptide L5 is screened out based on its gel formation property and bioavailability. L5 exerted a pH-switchable antimicrobial effect (pH 5.5) and formed biocompatible hydrogels at neutral pH (pH 7.4). The LysSYL-loaded L5 can assemble L5@LysSYL hydrogels, increase thermal stability, and exhibit the slow-release effect of LysSYL. Effective elimination of S. aureus is achieved by L5@LysSYL through bacterial membrane disruption and cell separation inhibition. Moreover, L5@LysSYL hydrogels exhibit great potential in promoting wound healing in a mouse wound model infected by MRSA. Furthermore, L5@LysSYL hydrogels are safe and can decrease the cytokine levels and increase the number of key factors for vessel formation, which contribute to wound healing. Overall, the self-assembling L5@LysSYL can effectively clean MRSA and promote wound healing, which suggests its potential as a pH-sensitive wound dressing for the management of wound infections.
Insights
A novel peptide hydrogel, L5@LysSYL, effectively combats methicillin-resistant Staphylococcus aureus (MRSA) wound infections. This pH-sensitive dressing promotes wound healing by releasing an endolysin and offers a promising solution for challenging infections.
Area of Science:
- Biotechnology
- Materials Science
- Infectious Diseases
Background:
- Staphylococcus aureus (S. aureus), particularly MRSA, causes difficult-to-treat wound infections.
- Acidic conditions (pH 4.5-6.5) in infected wounds limit the efficacy of antimicrobial agents like endolysins.
- Endolysins, such as LysSYL, show antistaphylococcal activity but suffer from instability and poor bioavailability in acidic environments.
Purpose of the Study:
- To develop a pH-sensitive drug delivery system for endolysin LysSYL to treat S. aureus wound infections.
- To create a self-assembling peptide hydrogel (L5) that enhances LysSYL stability and bioavailability.
- To evaluate the antimicrobial efficacy and wound healing potential of the L5@LysSYL hydrogel in a preclinical model.
Main Methods:
- Design and screening of self-assembling peptides, identifying L5 for its gelation and bioavailability.
- Loading LysSYL into the L5 peptide to form L5@LysSYL hydrogels.
- Assessment of L5@LysSYL hydrogel properties, including pH-switchable antimicrobial activity, stability, and drug release kinetics.
- Evaluation of L5@LysSYL in a mouse model of MRSA-infected wounds, including efficacy, safety, and wound healing promotion.
Main Results:
- Peptide L5 formed biocompatible hydrogels and exhibited pH-switchable antimicrobial activity.
- L5@LysSYL hydrogels enhanced LysSYL's thermal stability and enabled slow release.
- L5@LysSYL effectively eliminated S. aureus by disrupting bacterial membranes and inhibiting cell separation.
- In vivo studies demonstrated that L5@LysSYL promoted MRSA wound healing, reduced cytokine levels, and increased pro-angiogenic factors.
Conclusions:
- Self-assembling L5@LysSYL hydrogels provide an effective strategy for managing S. aureus wound infections.
- The pH-sensitive nature and enhanced stability of L5@LysSYL make it a promising candidate for advanced wound dressings.
- L5@LysSYL demonstrates significant potential for promoting wound healing and combating MRSA infections.
