Recent advances in antimicrobial peptide-based therapy

Optimization of antimicrobial peptide Smp43 as novel inhibitors of Cancer

Smp43 is a natural antimicrobial peptide derived from scorpion venom containing 43 amino acids, which inhibits the proliferation of various cancer cells, providing a new surrogate for antitumor drug discovery. However, Smp43 is large (Mw: 4653 Da) and unstable as a linear peptide. We truncated Smp43 to identify the key fragment and found that Smp(1-14) displayed significant antitumor activity. Subsequent optimization of Smp(1-14) led to a series of stapled peptides, among which SSmp6 demonstrated enhanced antitumor activity, stability, and membrane permeability compared to the linear peptides. Moreover, SSmp6 could decrease the phosphorylation of AKT, damage cancer cell membranes, and induce cell apoptosis. The results highlight the potential of SSmp6 as a lead stapled peptide for developing novel antitumor therapies. The study introduces a concept for using antimicrobial peptides to develop anticancer drugs.

Antifungal activity and mechanism of novel peptide Glycine max antimicrobial peptide (GmAMP) against fluconazole-resistant Candida tropicalis

Background

There is a pressing need to create innovative alternative treatment approaches considering the overuse of antifungal drugs causes the number of clinically isolated fluconazole-resistant Candida species to increase. Glycine max antimicrobial peptide (GmAMP) is a novel peptide screened by us using artificial intelligence modeling techniques, and pre-tests showed its strong antimicrobial activity against clinically fluconazole-resistant Candida tropicalis.

Methods

The study aimed to comprehensively investigate the antimicrobial activity and mechanisms of GmAMP against fluconazole-resistant C. tropicalis. The antifungal activity of GmAMP against fluconazole-resistant C. tropicalis was assessed by using broth microdilution method, growth and fungicidal kinetics, hypha transformation, and antibiofilm assay. To further uncover the potential mechanisms of action of GmAMP, we performed scanning electron microscopy, flow cytometry, cell membrane potential probe 3, 3'-Dipropylthiadicarbocyanine Iodide (DiSC3(5)), and reactive oxygen species (ROS) probe 2', 7'-Dichlorodihydrofluorescein diacetate (DCFH-DA) detection to assess the cellular morphology and structure, membrane permeability, membrane depolarization, and ROS accumulation, respectively. At the same time, we used cytotoxicity and degree of erythrocyte hemolysis assays to assess GmAMP's toxicity in vitro. Cytotoxicity and treatment efficacy were evaluated in vivo by utilizing the Galleria mellonella larvae infection model.

Results

GmAMP exhibited significant antifungal activity against fluconazole-resistant C. tropicalis with a minimum inhibitory concentration (MIC) of 25 µM and demonstrated fungicidal effects at 100 µM within 2 h. GmAMP prevented the transition from yeast to hypha morphology, inhibited the biofilm formation rate of 88.32%, and eradicated the mature biofilm rate of 58.28%. Additionally, GmAMP treatment at 100 µM caused cell structure damage in fluconazole-resistant C. tropicalis, whereas GmAMP treatment at concentrations ranging from 25 to 100 µM caused membrane permeability, depolarization of cell membrane potential, and intracellular ROS accumulation. Moreover, GmAMP enhanced the survival rate of 75% for G. mellonella with fluconazole-resistant C. tropicalis infection as well as reduced fungal burden in vivo by approximately 1.0 × 102 colony forming units per larva (CFU per larva).

Conclusion

GmAMP can disrupt the cell membrane of fluconazole-resistant C. tropicalis and also shows favorable safety and therapeutic efficacy in vivo. Accordingly, GmAMP has the potential to be an agent against drug-resistant fungi.

Combining Advanced Therapies with Alternative Treatments: A New Approach to Managing Antimicrobial Resistance?

Bacterial antimicrobial resistance (AMR) represents a critical public health threat, with increasing resistance compromising the effectiveness of treatments worldwide. Resistance trends, such as fluctuating benzylpenicillin resistance in Staphylococcus aureus, highlight the growing urgency, with projections indicating a rise in resistance to various antibiotics, including complete resistance to gentamicin and tetracycline by 2027. Despite substantial efforts to develop new antibiotics and drug delivery systems, these approaches must undergo rigorous clinical evaluation to ensure their safety and efficacy. In parallel, alternative therapies, such as phytotherapy and apitherapy, have garnered attention for their potential in combating infections. Natural substances like tea tree essential oils and propolis, which exhibit antimicrobial properties, are being increasingly incorporated into novel drug delivery systems. However, much of the research on these materials is not new, with several studies already exploring their effectiveness. To address the escalating AMR crisis, combining advanced therapies with alternative medicine could offer a promising solution. Advanced therapy products could target bacterial genomes and enhance the effectiveness of antibiotics and natural substances. This integrated approach remains underexplored in pre-clinical and clinical trials, presenting future research opportunities to develop more effective strategies in combating AMR. Given the rapid spread of resistant infections, there is an urgent need for innovative antimicrobial agents to overcome emerging resistance mechanisms and improve diagnoses and treatments.

Peptide Molecular Siege Machine: Breaking through Mycobacterium tuberculosis's Cellular Defenses for Precise Detection and Monitoring

This work introduces a peptide biosensor for detecting Mycobacterium tuberculosis (Mtb). The designed peptide probe exhibits specific affinity toward distinct components of Mtb. First, a peptide sequence is tailored to target hydrophobic long-chain fatty acids in the mycobacterial cell wall. Following this, an electrochemical potential scan releases a peptide sequence aimed at the intracellular molecular chaperones of Mtb. This sequence, upon penetration of the bacterial cell membrane, binds with molecular chaperones, which is crucial for Mtb survival and stress response. The biosensor incorporates complementary peptide sequences to capture chaperone-bound peptides back onto the substrate surface, allowing for their subsequent electrochemical detection. This multistep process enables selective and sequential interactions with Mtb components, minimizing interference from nontarget molecules. By integrating these innovative peptide probes into a wearable substrate using conductive polymer technology, the biosensor achieves high sensitivity and accuracy, offering a promising tool for the real-time monitoring of tuberculosis progression and treatment response.

Antimicrobial action and mechanism of piscidin against Helicobacter pylori

BACKGROUND

The rise of antibiotic-resistant Helicobacter pylori (Hp) strains is complicating the management of common gastrointestinal conditions such as gastritis and ulcers. In search of effective treatment options, antimicrobial peptides are being explored as a promising strategy.

METHODS

Leveraging bioinformatics, we dissected structural and sequence profiles of piscidin, an antimicrobial peptide. We investigated whether long-term piscidin exposure induces resistance in Hp strains by measuring their minimum inhibitory concentration. The Oxford cup test was applied to measure inhibition zones of piscidin against Hp strains. Following piscidin treatment, we monitored morphological alterations in Hp strains using scanning electron microscopy, and changes in urease activity, expressions of virulence factors CagA and UreB, and adenosine triphosphate levels. Cytotoxicity of piscidin was evaluated in AGS and 293T cells.

RESULTS

Piscidin inhibited proliferation of Hp strains, with a low propensity of inducing resistance. Delving into underlying mechanisms, we observed piscidin could alter morphology of Hp strains, suppress urease activity, and downregulate expressions of virulence factors CagA and UreB, while also reducing intracellular ATP levels. Piscidin had good security.

CONCLUSION

Piscidin is a potent antibacterial agent against Hp with low resistance risk, making it a safe and effective treatment candidate.

Combination of antimicrobial peptide and clinical antibiotic shows enhanced potency toward Acinetobacter baumannii infection

The continued development of novel antimicrobial treatment strategies is crucial for maintaining an effective therapeutic arsenal, and antimicrobial peptides (AMPs) exhibit promising activities against a wide range of pathogens. In this study, we tested the combined effects of an AMP, TP4-3, and meropenem on Acinetobacter baumannii, which is responsible for many severe infections and is associated with high rates of overall mortality and morbidity. This study aimed to develop an effective combination therapy for microbial infections. TP4-3 and meropenem were found to act synergistically toward Acinetobacter baumannii and exhibit an activity profile better than those of the individual compounds. TP4-3 is an antimicrobial peptide with proven activity, low toxicity and extended stability. This AMP was combined with meropenem and tested for efficacy against A. baumannii using a panel of in vitro and in vivo tests. The combination of TP4-3 and meropenem exhibited robust activity against Acinetobacter baumannii pathogens. In particular, the combined treatment demonstrated significant antibiofilm properties and a lower degree of induced resistance than meropenem alone. Additionally, the combination showed an excellent activity profile in in vivo studies. Thus, the combination of TP4-3 and meropenem appears to be an effective strategy to mitigate the detrimental consequences of infections caused by this clinically relevant pathogen. Since the combination of TP4-3 and meropenem displayed better activity than the individual compounds, this strategy of combining AMPs with clinical antibiotics may be suitable for development of clinical treatments targeting various microbial infections.

De novo-designed amphiphilic α-helical peptide Z2 exhibits broad-spectrum antimicrobial, anti-biofilm, and anti-inflammatory efficacy in acute Pseudomonas aeruginosa pneumonia

Antimicrobial peptides (AMPs) show considerable promise in combating bacterial infections due to their broad-spectrum efficacy, unique mechanisms of action, and resistance capabilities. In this study, we de novo designed a series of α-helical AMPs (Z1-Z6) with enhanced antimicrobial activity, anti-biofilm, and anti-inflammatory effects. The design incorporated isoleucine with long alkyl side chains and carefully balanced the positive charge and hydrophobicity. Among the designed peptides, Z2 demonstrated remarkable properties. In vitro assays revealed a high therapeutic index, with effective inhibition of 10 pathogenic and drug-resistant bacterial strains by disrupting cell membranes and interacting with bacterial genomes. Z2 also significantly suppressed biofilm formation and reduced reactive oxygen species production in RAW264.7 cells, leading to a decrease in inflammatory cytokine expression, thus showing anti-inflammatory activity. In a mouse model of acute Pseudomonas aeruginosa pneumonia, Z2 significantly improved survival rates, efficiently cleared bacteria from the lungs, and alleviated lung damage. Overall, Z2's unique design endows it with excellent antimicrobial, anti-biofilm, and anti-inflammatory activities, suggesting its great potential as a novel antimicrobial agent for further development. Future research will focus on the studying the drug formulations, elucidating the mechanisms underlying Z2's anti-inflammatory effects and exploring its therapeutic potential in other infection models.

Harnessing from Nature - Evolving Potential of Antimicrobial Peptide

Antimicrobial peptides (AMPs) are recognized as one of the most ancient components of innate immunity, playing a pivotal role as the first line of host defense systems. These evolutionarily conserved molecules have been identified in various organisms, from prokaryotes to humans. AMPs establish a delicate balanced relationship between host and microbes, by simultaneously regulating the biological activities of pathogens and commensal microbes. Given the escalating global concern over antibiotic resistance, there is an urgent need to explore alternative strategies to combat challenging infectious diseases. AMPs have emerged as promising candidates employed in clinical practice due to their sustainable bactericidal properties. Witnessed by deep understanding of AMPs actions toward host and bacteria, the potential applications of AMPs extend far beyond infection control. Emerging developments harnessed natural capabilities of AMPs to optimize their roles in modulating host signaling, treating diverse diseases, advancing biosensing and bioimaging technologies. In this Concept paper, we provide a comprehensive overview of the diversity and properties of AMPs. Additionally, we elaborate on the mechanisms underlying AMP activity and bacterial responses counteracting AMPs' functions. Most importantly, we discuss potential biomedical applications of AMPs and offer perspectives on their future development.

Exploring the potential of anticancer peptides as therapeutic agents for cancer treatment

Despite great advances in cancer identification and treatment, malignancies remain the primary cause of high morbidity and mortality worldwide. The drawbacks of conventional chemotherapy, such as severe toxicity, lack of specificity related to actively dividing cells, and resistance, can warrant the urgent need to develop an alternative approach to treat this disease. To overcome the drawbacks, researchers are attempting to deliver drugs to the site of action (targeted delivery) or to identify drugs that specifically target tumor cells. In this regard, highly cationic and amphipathic antimicrobial peptides are attracting the attention of researchers due to their potent anticancer activity, low cost of manufacture, and, most critically, tumor-targeting activity. A growing number of documents have shown that some of the mentioned peptides exhibited a broad spectrum of cytotoxic activity against cancer cells but not normal mammalian cells entitled as anticancer peptides. Due to their solubility, low toxicity, strong tumor penetration, high selectivity, and ability to be used alone or in conjunction with other conventional medications, anticancer peptides have the potential to become very successful cancer treatments in the future. This review provided an overview of the studies concerning anticancer peptide classification, modes of action, and selectivity, and also summarized some of the anticancer peptides developed for targeting different types of malignancies. The role of in silico methods or artificial intelligence in the design and discovery of anticancer peptides was briefly explained. Additionally, the current review addressed challenges in utilizing anticancer peptides for cancer therapy and highlighted peptides currently undergoing clinical trials.

A deformable SIS/HA composite hydrogel coaxial scaffold promotes alveolar bone regeneration after tooth extraction

After tooth extraction, alveolar bone absorbs unevenly, leading to soft tissue collapse, which hinders full regeneration. Bone loss makes it harder to do dental implants and repairs. Inspired by the biological architecture of bone, a deformable SIS/HA (Small intestinal submucosa/Hydroxyapatite) composite hydrogel coaxial scaffold was designed to maintain bone volume in the socket. The SIS/HA scaffold containing GL13K as the outer layer, mimicking compact bone, while SIS hydrogel loaded with bone marrow mesenchymal stem cells-derived exosomes (BMSCs-Exos) was utilized as the inner core of the scaffolds, which are like soft tissue in the skeleton. This coaxial scaffold exhibited a modulus of elasticity of 0.82 MPa, enabling it to adaptively fill extraction sockets and maintain an osteogenic space. Concurrently, the inner layer of this composite scaffold, enriched with BMSCs-Exos, promoted the proliferation and migration of human umbilical vein endothelial cells (HUVECs) and BMSCs into the scaffold interior (≈3-fold to the control), up-regulated the expression of genes related to osteogenesis (BMP2, ALP, RUNX2, and OPN) and angiogenesis (HIF-1α and VEGF). This induced new blood vessels and bone growth within the scaffold, addressing the issue of low bone formation rates at the center of defects. GL13K was released by approximately 40.87 ± 4.37 % within the first three days, exerting a localized antibacterial effect and further promoting vascularization and new bone formation in peripheral regions. This design aims to achieve an all-around and efficient bone restoration effect in the extraction socket using coaxial scaffolds through a dual internal and external mechanism.

Inhibitory Effect of Antimicrobial Peptides Bac7(17), PAsmr5-17 and PAβN on Bacterial Growth and Biofilm Formation of Multidrug-Resistant Acinetobacter baumannii

Acinetobacter (A.) baumannii is a major nosocomial pathogen in human and veterinary medicine. The emergence of certain international clones (ICs), often with multidrug-resistant (MDR) phenotypes and biofilm formation (BF), facilitates its spread in clinical environments. The global rise in antimicrobial resistance demands alternative treatment strategies, such as antimicrobial peptides (AMPs). In this study, 45 human and companion animal MDR-A. baumannii isolates, belonging to the globally spread IC1, IC2 and IC7, were tested for antimicrobial resistance and biofilm-associated genes (BAGs) and their capacity for BF. Of these, 13 were used to test the inhibitory effect of AMPs on bacterial growth (BG) and BF through the application of a crystal violet assay. The two novel AMP variants Bac7(17) (target cell inactivation) and Pasmr5-17 (efflux pump inhibition) and the well-known AMP phenylalanine-arginine-β-naphthylamide (PAβN) were tested at concentrations of 1.95 to 1000 µg/mL. Based on whole-genome sequence data, identical patterns of BAGs were detected within the same IC. AMPs inhibited BG and BF in a dose-dependent manner. Bac7(17) and PAsmr5-17 were highly effective against BG, with growth inhibition (GI) of >99% (62.5 and 125 µg/mL, respectively). PAβN achieved only 95.7% GI at 1000 µg/mL. Similar results were obtained for BF. Differences between the ICs were found for both GI and BF when influenced by AMPs. PAsmr5-17 had hardly any inhibitory effect on the BF of IC1 isolates, but for IC2 and IC7 isolates, 31.25 µg/mL was sufficient. Our data show that the susceptibility of animal MDR-A. baumannii to AMPs most likely resembles that of human isolates, depending on their assignment to a particular IC. Even low concentrations of AMPs had a significant effect on BG. Therefore, AMPs represent a promising alternative in the treatment of MDR-A. baumannii, either as the sole therapy or in combination with antibiotics.

Vibrio cholerae: Understanding a persistent pathogen in Sub-Saharan Africa and the East Mediterranean Region

Vibrio cholerae remains a significant public health threat in Sub-Saharan Africa and the East Mediterranean Region, where recurrent outbreaks are driven by inadequate water, sanitation, and hygiene infrastructure, climatic variability, and socio-political instability. This review explores the persistence of the pathogen in these regions, examining its epidemiology, environmental reservoirs, and genomic adaptations that enhance its survival and transmission. We highlight the impact of antimicrobial resistance and the role of climate change in cholera dynamics. Furthermore, we discuss current prevention and control strategies, including advancements in oral cholera vaccines, genomic surveillance, and microbiome-targeted interventions. Addressing these challenges requires a multifaceted approach that integrates sustainable sanitation improvements, strengthened disease surveillance, and innovative vaccination strategies. Understanding the persistence of V. cholerae in these high-risk regions is critical for developing effective, long-term mitigation strategies to reduce cholera morbidity and mortality.

Antimicrobial Peptides: A Promising Alternative to Conventional Antimicrobials for Combating Polymicrobial Biofilms

Polymicrobial biofilms adhere to surfaces and enhance pathogen resistance to conventional treatments, significantly contributing to chronic infections in the respiratory tract, oral cavity, chronic wounds, and on medical devices. This review examines antimicrobial peptides (AMPs) as a promising alternative to traditional antibiotics for treating biofilm-associated infections. AMPs, which can be produced as part of the innate immune response or synthesized therapeutically, have broad-spectrum antimicrobial activity, often disrupting microbial cell membranes and causing cell death. Many specifically target negatively charged bacterial membranes, unlike host cell membranes. Research shows AMPs effectively inhibit and disrupt polymicrobial biofilms and can enhance conventional antibiotics' efficacy. Preclinical and clinical research is advancing, with animal studies and clinical trials showing promise against multidrug-resistant bacteria and fungi. Numerous patents indicate increasing interest in AMPs. However, challenges such as peptide stability, potential cytotoxicity, and high production costs must be addressed. Ongoing research focuses on optimizing AMP structures, enhancing stability, and developing cost-effective production methods. In summary, AMPs offer a novel approach to combating biofilm-associated infections, with their unique mechanisms and synergistic potential with existing antibiotics positioning them as promising candidates for future treatments.

The Role and Mechanisms of Antimicrobial Peptides in Overcoming Multidrug-Resistant Bacteria

Multidrug-resistant (MDR) bacteria are becoming more and more common, which presents a serious threat to world health and could eventually render many of the antibiotics we currently use useless. The research and development of innovative antimicrobial tactics that can defeat these hardy infections are imperative in light of this predicament. Antimicrobial peptides (AMPs), which have attracted a lot of attention due to their distinct modes of action and capacity to elude conventional resistance mechanisms, are among the most promising of these tactics. As a promising substitute for conventional antibiotics, AMPs are a varied class of naturally occurring compounds that target bacteria membranes and disrupt cellular activities to demonstrate broad-spectrum antimicrobial activity. The objective of this study is to present a thorough summary of the current knowledge regarding AMP mechanisms against MDR bacteria, including immunological modulation, interactions with microbial membranes, and possible synergy with currently used antimicrobial drugs. In addition, we define the review's scope to include the most recent developments in AMP research, emphasizing the innovations' development, optimization, and therapeutic promise. We hope to emphasize the crucial role that AMPs will play in the future of antimicrobial therapy by bringing together recent research and highlighting current issues. We also hope to advocate for AMPs' continued research and development as part of a comprehensive strategy to counteract the growing threat of antibiotic resistance.

Detection strategies of infectious diseases via peptide-based electrochemical biosensors

Infectious diseases have threatened human life for as long as humankind has existed. One of the most crucial aspects of fighting against these infections is diagnosis to prevent disease spread. However, traditional diagnostic methods prove insufficient and time-consuming in the face of a pandemic. Therefore, studies focusing on detecting viruses causing these diseases have increased, with a particular emphasis on developing rapid, accurate, specific, user-friendly, and portable electrochemical biosensor systems. Peptides are used integral components in biosensor fabrication for several reasons, including various and adaptable synthesis protocols, long-term stability, and specificity. Here, we discuss peptide-based electrochemical biosensor systems that have been developed over the last decade for the detection of infectious diseases. In contrast to other reports on peptide-based biosensors, we have emphasized the following points i) the synthesis methods of peptides for biosensor applications, ii) biosensor fabrication approaches of peptide-based electrochemical biosensor systems, iii) the comparison of electrochemical biosensors with other peptide-based biosensor systems and the advantages and limitations of electrochemical biosensors, iv) the pros and cons of peptides compared to other biorecognition molecules in the detection of infectious diseases, v) different perspectives for future studies with the shortcomings of the systems developed in the past decade.

Designing Analogs of SAAP-148 with Enhanced Antimicrobial and Anti-LPS Activities

SAAP-148, a derivative of LL-37, exhibits a well-defined amphipathic structure and enhanced antimicrobial activity; however, it also displays significant cytotoxicity towards human cells. In this study, we employed Lys-scan to produce a series of amphiphilic SAAP-148 analogs derived from the SAAP-148 sequence to investigate the impact of the distribution of positively charged residues on the biological viability of the antimicrobial peptides (AMPs). The physical properties and biological activity of the designed peptides were subsequently compared. The substitution of lysine resulted in an increase in the overall charge of SAAP-148 and a decrease in its overall hydrophobicity and hyd. moment, except for SAAP-10 where an analogue substitution occurred at the 18th residue. The replacement of lysine led to a reduction in hemolytic activity compared to SAAP-148, with slightly higher haemolysis rates observed in SAAP-11 and SAAP-13. The cytotoxicity of peptides towards human normal lung epithelial cells (BEAS-2B) was closely linked to their haemolytic activity, indicating that substituting lysine may mitigate the cytotoxic effects of SAAP-148. Additionally, the arrangement of positively charged residues in the peptides significantly influenced its antimicrobial activity. Our findings suggest that the positioning of a positively charged residue has a significant impact on the biophysical properties of the peptide. Additionally, the substitution of lysine at different positions demonstrates an influence on the anti-lipopolysaccharide (anti-LPS) activity of SAAP-148. These discoveries provide valuable insights for the design and optimization of antimicrobial peptides, which will be advantageous for the future development of antimicrobial agents.

Screening and heterologous expression of an antimicrobial peptide SCAK33 with broad-spectrum antimicrobial activity resourced from sea cucumber proteome

Antimicrobial peptides (AMPs) are a family of short defense proteins that are naturally produced by all organisms and have great potential as effective substitutes for small-molecule antibiotics. The present study aims to excavate AMPs from sea cucumbers and achieve their heterologous expression in prokaryotic Escherichia coli. Using MytC as a probe, a cysteine-stabilized peptide SCAK33 with broad-spectrum antimicrobial activity was discovered from the proteome of Apostichopus japonicas. The SCAK33 showed inhibitory effects on both gram positive and gram negative bacteria with MICs of 3-28 μM, and without significant hemolysis activity in rat blood erythrocyte. Especially, it exhibited good antimicrobial activity against Bacillus megaterium, B. subtilis, and Vibrio parahaemolyticus with the MIC of 3, 7, and 7 μM, respectively. After observation by scanning electronic microscopy (SEM) and confocal laser scanning microscope (CLSM), it was found that the cell membrane of bacteria was severely damaged. Furthermore, the recombinant SCAK33 (reSCAK33) was heterologously expressed by fusion with SUMO tag in E. coli BL21(DE3), and the protein yield reached 70 mg/L. The research will supplement the existing quantity of sea cucumber AMPs and provide data support for rapid mining and biological preparation of sea cucumber AMPs.

The pH-Insensitive Antimicrobial and Antibiofilm Activities of the Frog Skin Derived Peptide Esc(1-21): Promising Features for Novel Anti-Infective Drugs

The number of antibiotic-resistant microbial infections is dramatically increasing, while the discovery of new antibiotics is significantly declining. Furthermore, the activity of antibiotics is negatively influenced by the ability of bacteria to form sessile communities, called biofilms, and by the microenvironment of the infection, characterized by an acidic pH, especially in the lungs of patients suffering from cystic fibrosis (CF). Antimicrobial peptides represent interesting alternatives to conventional antibiotics, and with expanding properties. Here, we explored the effects of an acidic pH on the antimicrobial and antibiofilm activities of the AMP Esc(1-21) and we found that it slightly lost activity (from 2- to 4-fold) against the planktonic form of a panel of Gram-negative bacteria, with respect to a ≥ 32-fold of traditional antibiotics. Furthermore, it retained its activity against the sessile form of these bacteria grown in media with a neutral pH, and showed similar or higher effectiveness against the biofilm form of bacteria grown in acidic media, simulating a CF-like acidic microenvironment, compared to physiological conditions.

Screening of Short-Chain Antimicrobial Peptide LKARI with Broad-Spectrum Bactericidal Properties and Its Application in Promoting Wound Healing

Due to the extensive use of antibiotics, many highly resistant bacteria and extensively resistant bacteria have been produced. In recent years, the increase of drug-resistant bacteria and the resulting proliferation of drug-resistant bacteria have increased the incidence of hospital-acquired infections and caused great harm to human health. Antimicrobial peptides (AMPs) are considered to be an innovative antibiotic and belong to the latest advances in this field. We designed a polypeptide and verified its low minimum inhibitory concentration and broad-spectrum activity against Gram-positive bacteria, Gram-negative bacteria, and fungi in microbiology and pharmacology. Several experiments have confirmed that the screened antimicrobial peptides have significant antidrug resistance and also show significant therapeutic properties in the treatment of systemic bacterial infections. In addition, through our experimental research, it was proved that the antibacterial hydrogel composed of poly(vinyl alcohol), sodium alginate, and antimicrobial peptides had excellent antibacterial properties and showed good wound healing ability.