1
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van Zyl EM, Coburn JM. Functionalization of Bacterial Cellulose with the Antimicrobial Peptide KR-12 via Chimerical Cellulose-Binding Peptides. Int J Mol Sci 2024; 25:1462. [PMID: 38338739 PMCID: PMC10855235 DOI: 10.3390/ijms25031462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 01/16/2024] [Accepted: 01/20/2024] [Indexed: 02/12/2024] Open
Abstract
Bacterial-derived cellulose (BC) has been studied as a promising material for biomedical applications, including wound care, due to its biocompatibility, water-holding capacity, liquid/gas permeability, and handleability properties. Although BC has been studied as a dressing material for cutaneous wounds, to date, BC inherently lacks antibacterial properties. The current research utilizes bifunctional chimeric peptides containing carbohydrate binding peptides (CBP; either a short version or a long version) and an antimicrobial peptide (AMP), KR-12. The secondary structure of the chimeric peptides was evaluated and confirmed that the α-helix structure of KR-12 was retained for both chimeric peptides evaluated (Long-CBP-KR12 and Short-CBP-KR12). Chimeric peptides and their individual components were assessed for cytotoxicity, where only higher concentrations of Short-CBP and longer timepoints of Short-CBP-KR12 exposure exhibited negative effects on metabolic activity, which was attributed to solubility issues. All KR-12-containing peptides exhibited antibacterial activity in solution against Escherichia coli (E. coli) and Pseudomonas aeruginosa (P. aeruginosa). The lipopolysaccharide (LPS) binding capability of the peptides was evaluated and the Short-CBP-KR12 peptide exhibited enhanced LPS-binding capabilities compared to KR-12 alone. Both chimeric peptides were able to bind to BC and were observed to be retained on the surface over a 7-day period. All functionalized materials exhibited no adverse effects on the metabolic activity of both normal human dermal fibroblasts (NHDFs) and human epidermal keratinocyte (HaCaT) epithelial cells. Additionally, the BC tethered chimeric peptides exhibited antibacterial activity against E. coli. Overall, this research outlines the design and evaluation of chimeric CBP-KR12 peptides for developing antimicrobial BC membranes with potential applications in wound care.
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Affiliation(s)
| | - Jeannine M. Coburn
- Department of Biomedical Engineering, Worcester Polytechnic Institute, Worcester, MA 01609, USA
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2
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Memariani M, Memariani H. Antifungal properties of cathelicidin LL-37: current knowledge and future research directions. World J Microbiol Biotechnol 2023; 40:34. [PMID: 38057654 DOI: 10.1007/s11274-023-03852-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 11/22/2023] [Indexed: 12/08/2023]
Abstract
The threat of fungal diseases is substantially underestimated worldwide, but they have serious consequences for humans, animals, and plants. Given the limited number of existing antifungal drugs together with the emergence of drug-resistant strains, many researchers have actively sought alternatives or adjuvants to antimycotics. The best way to tackle these issues is to unearth potential antifungal agents with new modes of action. Antimicrobial peptides are being hailed as a promising source of novel antimicrobials since they exhibit rapid and broad-spectrum microbicidal activities with a reduced likelihood of developing drug resistance. Recent years have witnessed an explosion in knowledge on microbicidal activity of LL-37, the sole human cathelicidin. Herein, we provide a summary of the current understanding about antifungal properties of LL-37, with particular emphasis on its molecular mechanisms. We further illustrate fruitful areas for future research. LL-37 is able to inhibit the growth of clinically and agronomically relevant fungi including Aspergillus, Candida, Colletotrichum, Fusarium, Malassezia, Pythium, and Trichophyton. Destruction of the cell wall integrity, membrane permeabilization, induction of oxidative stress, disruption of endoplasmic reticulum homeostasis, formation of autophagy-like structures, alterations in expression of numerous fungal genes, and inhibition of cell cycle progression are the key mechanisms underlying antifungal effects of LL-37. Burgeoning evidence also suggests that LL-37 may act as a potential anti-virulence peptide. It is hoped that this review will not only motivate researchers to conduct more detailed studies in this field, but also inspire further innovations in the design of LL-37-based drugs for the treatment of fungal infections.
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Affiliation(s)
- Mojtaba Memariani
- Department of Medical Microbiology, Tehran University of Medical Sciences, Tehran, Iran
| | - Hamed Memariani
- Department of Medical Microbiology, Tehran University of Medical Sciences, Tehran, Iran.
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3
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Hatlen RR, Rajagopalan P. Investigating Trans-differentiation of Glioblastoma Cells in an In Vitro 3D Model of the Perivascular Niche. ACS Biomater Sci Eng 2023. [PMID: 37129167 DOI: 10.1021/acsbiomaterials.2c01310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Glioblastoma multiforme (GBM) is the deadliest form of brain cancer, responsible for over 50% of adult brain tumors. A specific region within the GBM environment is known as the perivascular niche (PVN). This area is defined as within approximately 100 μm of vasculature and plays an important role in the interactions between endothelial cells (ECs), astrocytes, GBM cells, and stem cells. We have designed a 3D in vitro model of the PVN comprising either collagen Type 1 or HyStem-C, human umbilical vein ECs (HUVECs), and LN229 (GBM) cells. HUVECs were encapsulated within the hydrogels to form vascular networks. After 7 days, LN229 cells were co-cultured to investigate changes in both cell types. Over a 14 day culture period, we measured alterations in HUVEC networks, the contraction of the hydrogels, trans-differentiation of LN229 cells, and the concentrations of two chemokines; CXCL12 and TGF-β. Increased cellular proliferation ranging from 10- to 16-fold was exhibited in co-cultures from days 8 to 14. This was accompanied with a decrease in the height of hydrogels of up to 68%. These changes in the biomaterial scaffold indicate that LN229-HUVEC interactions promote changes to the matrix. TGF-β and CXCL12 secretion increased approximately 2-2.6-fold each from day 8 to 14 in all co-cultures. The expression of CXCL12 correlated with cell colocalization, indicating a chemotactic role in enabling the migration of LN229 cells toward HUVECs in co-cultures. von Willebrand factor (vWF) was co-expressed with glial fibrillary acidic protein (GFAP) in up to 15% of LN229 cells after 24 h in co-culture. Additionally, when LN229 cells were co-cultured with human brain microvascular ECs, the percentages of GFAP+/vWF+ cells were up to 20% higher than that in co-cultures with HUVECs in collagen (2.2 mg/mL) and HyStem-C gels on day 14. The expression of vWF indicates the early stages of trans-differentiation of LN229 cells to an EC phenotype. Designing in vitro models of trans-differentiation may provide additional insights into how vasculature and cellular phenotypes are altered in GBM.
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Affiliation(s)
- Rosalyn R Hatlen
- Department of Chemical Engineering, Virginia Tech, Blacksburg, Virginia 24061, United States
| | - Padmavathy Rajagopalan
- Department of Chemical Engineering, Virginia Tech, Blacksburg, Virginia 24061, United States
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Ersanli C, Tzora A, Skoufos I, Voidarou CC, Zeugolis DI. Recent Advances in Collagen Antimicrobial Biomaterials for Tissue Engineering Applications: A Review. Int J Mol Sci 2023; 24:ijms24097808. [PMID: 37175516 PMCID: PMC10178232 DOI: 10.3390/ijms24097808] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 04/09/2023] [Accepted: 04/18/2023] [Indexed: 05/15/2023] Open
Abstract
Biomaterial-based therapies have been receiving attention for treating microbial infections mainly to overcome the increasing number of drug-resistant bacterial strains and off-target impacts of therapeutic agents by conventional strategies. A fibrous, non-soluble protein, collagen, is one of the most studied biopolymers for the development of antimicrobial biomaterials owing to its superior physicochemical, biomechanical, and biological properties. In this study, we reviewed the different approaches used to develop collagen-based antimicrobial devices, such as non-pharmacological, antibiotic, metal oxide, antimicrobial peptide, herbal extract-based, and combination approaches, with a particular focus on preclinical studies that have been published in the last decade.
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Affiliation(s)
- Caglar Ersanli
- Laboratory of Animal Science, Nutrition and Biotechnology, Department of Agriculture, University of Ioannina, 47100 Arta, Greece
- Laboratory of Animal Health, Food Hygiene and Quality, Department of Agriculture, University of Ioannina, 47100 Arta, Greece
- Regenerative, Modular & Developmental Engineering Laboratory (REMODEL), Charles Institute of Dermatology, Conway Institute of Biomolecular and Biomedical Research, School of Mechanical and Materials Engineering, University College Dublin, D04 V1W8 Dublin, Ireland
| | - Athina Tzora
- Laboratory of Animal Health, Food Hygiene and Quality, Department of Agriculture, University of Ioannina, 47100 Arta, Greece
| | - Ioannis Skoufos
- Laboratory of Animal Science, Nutrition and Biotechnology, Department of Agriculture, University of Ioannina, 47100 Arta, Greece
| | - Chrysoula Chrysa Voidarou
- Laboratory of Animal Health, Food Hygiene and Quality, Department of Agriculture, University of Ioannina, 47100 Arta, Greece
| | - Dimitrios I Zeugolis
- Regenerative, Modular & Developmental Engineering Laboratory (REMODEL), Charles Institute of Dermatology, Conway Institute of Biomolecular and Biomedical Research, School of Mechanical and Materials Engineering, University College Dublin, D04 V1W8 Dublin, Ireland
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5
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Zamboni F, Wong CK, Collins MN. Hyaluronic acid association with bacterial, fungal and viral infections: Can hyaluronic acid be used as an antimicrobial polymer for biomedical and pharmaceutical applications? Bioact Mater 2023; 19:458-473. [PMID: 35574061 PMCID: PMC9079116 DOI: 10.1016/j.bioactmat.2022.04.023] [Citation(s) in RCA: 34] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 04/05/2022] [Accepted: 04/23/2022] [Indexed: 12/21/2022] Open
Abstract
The relationships between hyaluronic acid (HA) and pathological microorganisms incite new understandings on microbial infection, tissue penetration, disease progression and lastly, potential treatments. These understandings are important for the advancement of next generation antimicrobial therapeutical strategies for the control of healthcare-associated infections. Herein, this review will focus on the interplay between HA, bacteria, fungi, and viruses. This review will also comprehensively detail and discuss the antimicrobial activity displayed by various HA molecular weights for a variety of biomedical and pharmaceutical applications, including microbiology, pharmaceutics, and tissue engineering.
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Affiliation(s)
- Fernanda Zamboni
- Bernal Institute, School of Engineering, University of Limerick, Ireland
- Health Research Institute, University of Limerick, Ireland
| | - Chun Kwok Wong
- Department of Chemical Pathology, The Chinese University of Hong Kong, Hong Kong Special Administrative Region
| | - Maurice N. Collins
- Bernal Institute, School of Engineering, University of Limerick, Ireland
- Health Research Institute, University of Limerick, Ireland
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6
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Li K, Zhang L, Li J, Xue Y, Zhou J, Han Y. pH-Responsive ECM Coating on Ti Implants for Antibiosis in Reinfected Models. ACS APPLIED BIO MATERIALS 2022; 5:344-354. [PMID: 35014807 DOI: 10.1021/acsabm.1c01143] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Reinfection of implants during their service life causes troubles to patients. Traditionally, physical loading or chemical bonding of antibacterial agents on implant surfaces cannot settle the repeated bacterial invasion after a period of implantation. In this work, a pH-responsive extracellular matrix (ECM) coating was fabricated on Ti. It consisted of hydroxyapatite (HA) nanorods, antimicrobial peptide (AMP) cross-linked collagen I nanonets (CA nanonets), and physically loaded AMPs. CA nanonets formed in the interspaces of HA nanorods and had an average pore size of 46.5 nm. With the increase in the weight ratio of AMP cross-linkers in collagen I (from 0 to 1:3), the isoelectric points of CA nanonets increased. CA nanonets linked with 50 wt % of AMPs (HCA1) had an isoelectric point of about 7, and their zeta potential shifted from electronegativity to electropositivity when the pH value changed from 7.4 to 6.0. Compared with other nanonets, HCA1 showed a pH-responsive blast release of physically loaded AMPs. It was due to the electrostatic repulsion between the physically adsorbed AMPs and HCA1 after a shift in the potential. In vitro, all the CA nanonets were cytocompatible and exhibited significant short-term antibacterial performance; however, just HCA1 showed outstanding long-time responsive antibacterial activity; in vivo, HCA1 inhibited bacterial infection and suppressed the inflammatory response, especially in a reinfected model, indicating its potential application in Ti implants to mitigate the risk of reinfection.
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Affiliation(s)
- Kai Li
- State-key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, China.,Department of Biomaterials, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University & Shandong Key Laboratory of Oral Tissue Regeneration & Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration, Jinan 250012, Shandong, China
| | - Lan Zhang
- State-key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, China
| | - Jianhua Li
- Department of Biomaterials, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University & Shandong Key Laboratory of Oral Tissue Regeneration & Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration, Jinan 250012, Shandong, China
| | - Yang Xue
- State-key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, China
| | - Jianhong Zhou
- Institute of Physics & Optoelectronics Technology, Advanced Titanium Alloys and Functional Coatings Cooperative Innovation Center, Baoji University of Arts and Sciences, Baoji 721016, China
| | - Yong Han
- State-key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, China
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7
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Ridyard KE, Overhage J. The Potential of Human Peptide LL-37 as an Antimicrobial and Anti-Biofilm Agent. Antibiotics (Basel) 2021; 10:antibiotics10060650. [PMID: 34072318 PMCID: PMC8227053 DOI: 10.3390/antibiotics10060650] [Citation(s) in RCA: 76] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 05/20/2021] [Accepted: 05/25/2021] [Indexed: 02/06/2023] Open
Abstract
The rise in antimicrobial resistant bacteria threatens the current methods utilized to treat bacterial infections. The development of novel therapeutic agents is crucial in avoiding a post-antibiotic era and the associated deaths from antibiotic resistant pathogens. The human antimicrobial peptide LL-37 has been considered as a potential alternative to conventional antibiotics as it displays broad spectrum antibacterial and anti-biofilm activities as well as immunomodulatory functions. While LL-37 has shown promising results, it has yet to receive regulatory approval as a peptide antibiotic. Despite the strong antimicrobial properties, LL-37 has several limitations including high cost, lower activity in physiological environments, susceptibility to proteolytic degradation, and high toxicity to human cells. This review will discuss the challenges associated with making LL-37 into a viable antibiotic treatment option, with a focus on antimicrobial resistance and cross-resistance as well as adaptive responses to sub-inhibitory concentrations of the peptide. The possible methods to overcome these challenges, including immobilization techniques, LL-37 delivery systems, the development of LL-37 derivatives, and synergistic combinations will also be considered. Herein, we describe how combination therapy and structural modifications to the sequence, helicity, hydrophobicity, charge, and configuration of LL-37 could optimize the antimicrobial and anti-biofilm activities of LL-37 for future clinical use.
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8
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Lin X, Wang R, Mai S. Advances in delivery systems for the therapeutic application of LL37. J Drug Deliv Sci Technol 2020. [DOI: 10.1016/j.jddst.2020.102016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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9
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Patrulea V, Borchard G, Jordan O. An Update on Antimicrobial Peptides (AMPs) and Their Delivery Strategies for Wound Infections. Pharmaceutics 2020; 12:E840. [PMID: 32887353 PMCID: PMC7560145 DOI: 10.3390/pharmaceutics12090840] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 08/22/2020] [Accepted: 08/28/2020] [Indexed: 12/13/2022] Open
Abstract
Bacterial infections occur when wound healing fails to reach the final stage of healing, which is usually hindered by the presence of different pathogens. Different topical antimicrobial agents are used to inhibit bacterial growth due to antibiotic failure in reaching the infected site, which is accompanied very often by increased drug resistance and other side effects. In this review, we focus on antimicrobial peptides (AMPs), especially those with a high potential of efficacy against multidrug-resistant and biofilm-forming bacteria and fungi present in wound infections. Currently, different AMPs undergo preclinical and clinical phase to combat infection-related diseases. AMP dendrimers (AMPDs) have been mentioned as potent microbial agents. Various AMP delivery strategies that are used to combat infection and modulate the healing rate-such as polymers, scaffolds, films and wound dressings, and organic and inorganic nanoparticles-have been discussed as well. New technologies such as Clustered Regularly Interspaced Short Palindromic Repeat (CRISPR)-associated protein (CRISPR-Cas) are taken into consideration as potential future tools for AMP delivery in skin therapy.
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Affiliation(s)
- Viorica Patrulea
- Institute of Pharmaceutical Sciences of Western Switzerland, University of Geneva, 1 Rue Michel Servet, 1211 Geneva, Switzerland;
- Section of Pharmaceutical Sciences, University of Geneva, 1 Rue Michel Servet, 1211 Geneva, Switzerland
| | - Gerrit Borchard
- Institute of Pharmaceutical Sciences of Western Switzerland, University of Geneva, 1 Rue Michel Servet, 1211 Geneva, Switzerland;
- Section of Pharmaceutical Sciences, University of Geneva, 1 Rue Michel Servet, 1211 Geneva, Switzerland
| | - Olivier Jordan
- Institute of Pharmaceutical Sciences of Western Switzerland, University of Geneva, 1 Rue Michel Servet, 1211 Geneva, Switzerland;
- Section of Pharmaceutical Sciences, University of Geneva, 1 Rue Michel Servet, 1211 Geneva, Switzerland
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10
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Borro BC, Malmsten M. Complexation between antimicrobial peptides and polyelectrolytes. Adv Colloid Interface Sci 2019; 270:251-260. [PMID: 31301601 DOI: 10.1016/j.cis.2019.07.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2019] [Revised: 07/02/2019] [Accepted: 07/02/2019] [Indexed: 12/18/2022]
Abstract
As a result of increasing bacterial resistance against antibiotics, we are facing an emerging health crisis, in which 'simple' infections may no longer be treatable. One class of molecules attracting interest in this context is antimicrobial peptides (AMPs), and considerable research efforts have been directed to identifying selective and potent AMPs. In addition, since in vivo delivery of AMPs is challenging, there is an emerging awareness that successful development of AMP therapeutics can be facilitated by careful design of AMPs delivery systems. In the present overview, we discuss polyelectrolyte complexation as a strategy to deliver AMPs. In doing so, key factors for AMP-polyelectrolyte complexation are illustrated for AMP-polyelectrolyte nanoparticle formation, as well as for AMP incorporation in polyelectrolyte microgels and multilayer structures, and consequences of these for functional performance exemplified.
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11
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Querido MM, Aguiar L, Neves P, Pereira CC, Teixeira JP. Self-disinfecting surfaces and infection control. Colloids Surf B Biointerfaces 2019; 178:8-21. [PMID: 30822681 PMCID: PMC7127218 DOI: 10.1016/j.colsurfb.2019.02.009] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 02/04/2019] [Accepted: 02/05/2019] [Indexed: 12/27/2022]
Abstract
According to World Health Organization, every year in the European Union, 4 million patients acquire a healthcare associated infection. Even though some microorganisms represent no threat to healthy people, hospitals harbor different levels of immunocompetent individuals, namely patients receiving immunosuppressors, with previous infections, or those with extremes of age (young children and elderly), requiring the implementation of effective control measures. Public spaces have also been found an important source of infectious disease outbreaks due to poor or none infection control measures applied. In both places, surfaces play a major role on microorganisms' propagation, yet they are very often neglected, with very few guidelines about efficient cleaning measures and microbiological assessment available. To overcome surface contamination problems, new strategies are being designed to limit the microorganisms' ability to survive over surfaces and materials. Surface modification and/or functionalization to prevent contamination is a hot-topic of research and several different approaches have been developed lately. Surfaces with anti-adhesive properties, with incorporated antimicrobial substances or modified with biological active metals are some of the strategies recently proposed. This review intends to summarize the problems associated with contaminated surfaces and their importance on infection spreading, and to present some of the strategies developed to prevent this public health problem, namely some already being commercialized.
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Affiliation(s)
- Micaela Machado Querido
- National Institute of Health, Environmental Health Department, Porto, Portugal; EPIUnit - Institute of Public Health, University of Porto, Porto, Portugal
| | - Lívia Aguiar
- National Institute of Health, Environmental Health Department, Porto, Portugal
| | - Paula Neves
- National Institute of Health, Environmental Health Department, Porto, Portugal
| | - Cristiana Costa Pereira
- National Institute of Health, Environmental Health Department, Porto, Portugal; EPIUnit - Institute of Public Health, University of Porto, Porto, Portugal.
| | - João Paulo Teixeira
- National Institute of Health, Environmental Health Department, Porto, Portugal; EPIUnit - Institute of Public Health, University of Porto, Porto, Portugal
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12
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Yoshida K, Suzuki S, Kawada-Matsuo M, Nakanishi J, Hirata-Tsuchiya S, Komatsuzawa H, Yamada S, Shiba H. Heparin-LL37 complexes are less cytotoxic for human dental pulp cells and have undiminished antimicrobial and LPS-neutralizing abilities. Int Endod J 2019; 52:1327-1343. [PMID: 31002379 DOI: 10.1111/iej.13130] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 04/12/2019] [Indexed: 12/13/2022]
Abstract
AIM To investigate whether glycosaminoglycans (GAGs) binding to high-dose LL37 eliminates its cytotoxicity to dental pulp cells (hDPCs) whilst retaining undiminished antimicrobial and LPS-neutralizing abilities. METHODOLOGY hDPCs were stimulated with varying concentrations of LL37, and their cell viability was analysed by MTT. Then, high-dose LL37 (10 μmol L-1 ) was bound to varying concentrations of three GAGs, heparin, chondroitin sulphate and hyaluronic acid, and their cytotoxic effects on hDPCs and antimicrobial effects were evaluated and compared. Furthermore, the LPS-neutralizing ability of heparin (5 μg mL-1 )-LL37 (10 μmol L-1 ) complexes, which were found to be less cytotoxic for hDPCs with undiminished antimicrobial ability, was investigated. Statistical analysis was performed using one-way analysis of variance (anova), followed by Dunnett's test. P values below 0.05 were considered significant. RESULTS LL37 significantly reduced the cell viability of hDPCs in a dose-dependent manner (P < 0.01). LL37 (10 μmol L-1 ) binding to heparin within a limited concentration range (2~6 μg mL-1 ) eliminated the cytotoxicity for hDPCs (P < 0.01) whilst exerting potent antimicrobial effects against Streptococcus mutans, Streptococcus sobrinus, Streptococcus salivarius, Aggegatibacter actinomycetemcomitans and Escherichia coli. LL37 (10 μmol L-1 ) binding to chondroitin sulphate exhibited similar functions (P < 0.01); however, the effective chondroitin sulphate concentration was highly restricted (3 μg mL-1 ). LL37 (10 μmol L-1 ) binding to hyaluronic acid was unable to abrogate the cytotoxicity of LL37 even at higher concentrations (10 and 100 μg mL-1 ). Moreover, exogenous addition of LPS dose-dependently reduced the amount of LL37 precipitated with the heparin-LL37 agarose beads (P < 0.01), and the released LL37 simultaneously neutralized the pro-inflammatory ability of LPS in macrophages (P < 0.01). CONCLUSIONS Heparin-LL37 complexes generated at suitable concentration ratios are easy to make, are less cytotoxic and are broad-range antimicrobial materials that can neutralize LPS by providing LL37 in accordance with the amount of free LPS. They may be a potential treatment to save dental pulp tissue from the acute inflammation exacerbated by invading bacteria and the LPS they release.
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Affiliation(s)
- K Yoshida
- Department of Biological Endodontics, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - S Suzuki
- Department of Biological Endodontics, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.,Department of Periodontology and Endodontology, Tohoku University Graduate School of Dentistry, Sendai, Japan
| | - M Kawada-Matsuo
- Department of Oral Microbiology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - J Nakanishi
- Department of Biological Endodontics, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - S Hirata-Tsuchiya
- Department of Biological Endodontics, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - H Komatsuzawa
- Department of Oral Microbiology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - S Yamada
- Department of Periodontology and Endodontology, Tohoku University Graduate School of Dentistry, Sendai, Japan
| | - H Shiba
- Department of Biological Endodontics, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
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13
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Mechanistic predictions of the influence of collagen-binding domain sequences on human LL37 interactions with model lipids using quartz crystal microbalance with dissipation. Biointerphases 2019; 14:021006. [PMID: 31039613 DOI: 10.1116/1.5089759] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Modifications of human-derived antimicrobial peptide LL37 with collagen binding domains (CBD-LL37) hold promise as alternatives to antibiotics due to their wider therapeutic ratio than unmodified LL37 when interacting with collagen substrates such as commercial wound dressings. However, CBD-LL37 lipid membrane interaction mechanisms (against both mammalian and bacterial lipids) are not well understood. Our goal was to develop a mechanistic explanation of how CBDs modulate peptide-lipid interactions leading to their observed bioactivities, in order to better understand their potential for clinical applications. The authors studied time- and concentration-dependent interactions of CBD-LL37 modified with collagenase (cCBD) and fibronectin (fCBD) CBDs, with zwitterionic and anionic supported lipid bilayers, in order to model mammalian erythrocytes and bacterial cells, respectively. Quartz crystal microbalance with dissipation monitoring (QCM-D) was used to characterize peptide-lipid interactions at concentrations in the immunomodulatory (0.5-1.0 μM), antimicrobial (1.0-5.0 μM), and cytotoxic (5.0-10.0 μM) ranges. Their prior work with zwitterionic membranes demonstrated that cCBD-LL37 formed transmembrane pores while fCBD-LL37 underwent surface adsorption. Our goal in this study is to better interpret these results, by investigating the data at a wider concentration range and for two types of lipids, and by applying the Voigt-Kelvin viscoelastic model to calculate thickness and density changes of the peptide-lipid films as a function of time and concentration, thus providing information to help build detailed mechanisms of peptide/bilayer interactions. For pore-forming cCBD-LL37 and unmodified LL37, they found that there was a relationship between layer thicknesses and pore formation, which was attributed to different peptide orientation changes influenced by bilayer charge prior to pore formation. Specifically, cCBD-LL37 at 0.5 and 1.0 μM demonstrated higher thicknesses on zwitterionic than anionic membranes, indicating that prior to insertion into zwitterionic membranes, it orients perpendicular to the surface, which was also consistent with the higher dissipation changes observed on zwitterionic membranes. fCBD-LL37 demonstrated a bilayer adsorption mechanism with a preference toward anionic lipids. Adsorption of fCBD-LL37 onto anionic lipids demonstrated a rapid first adsorption step that transitioned depending on the number of fCBD-LL37 molecules on the bilayer. For this peptide at higher concentrations, greater dissipation changes were observed than for fCBD-LL37 physically adsorbed onto surfaces without bilayers. This suggests that peptide-peptide interactions promoted by the fCBD domain dominated after saturation. The development of a structure-function relationship for cCBD-LL37 and fCBD-LL37 demonstrates promise for using QCM-D predictions to inform the rational design of novel, antimicrobial, and noncytotoxic CBD-LL37 for clinical applications.
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14
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Fibroblasts stimulate macrophage migration in interconnected extracellular matrices through tunnel formation and fiber alignment. Biomaterials 2019; 209:88-102. [PMID: 31030083 DOI: 10.1016/j.biomaterials.2019.03.044] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 03/26/2019] [Accepted: 03/28/2019] [Indexed: 02/07/2023]
Abstract
In vivo, macrophages and fibroblasts navigate through and remodel the three-dimensional (3D) extra-cellular matrix (ECM). The orientation of fibers, the porosity, and degree of cross-linking can change the interconnectivity of the ECM and affect cell migration. In turn, migrating cells can alter their microenvironment. To study the relationships between ECM interconnectivity and migration of cells, we assembled collagen hydrogels with dense (DCN) or with loosely interconnected networks (LCN). We find that in DCNs, RAW 264.7 macrophages in monocultures were virtually stationary. In DCN co-cultures, Balb/c 3T3 fibroblasts created tunnels that provided conduits for macrophage migration. In LCNs, fibroblasts aligned fibers up to a distance of 100 μm, which provided tracks for macrophages. Intra-cellular and extra-cellular fluorescent fragments of internalized and degraded collagen were detected inside both cell types as well as around their cell peripheries. Macrophages expressed higher levels of urokinase-type plasminogen activator receptor associated protein (uPARAP)/mannose receptor 1 (CD206) compared to α2β1 indicating that collagen internalization in these cells occurred primarily via integrin-independent mechanisms. Network remodeling indicated by higher Young's modulus was observed in fibroblast monocultures as a result of TGF-β secretion. This work unveils new roles for fibroblasts in forming tunnels in networked ECM to modulate macrophage migration.
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Design of Antimicrobial Peptides: Progress Made with Human Cathelicidin LL-37. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1117:215-240. [PMID: 30980360 DOI: 10.1007/978-981-13-3588-4_12] [Citation(s) in RCA: 85] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The incorporation of the innate immune system into humans is essential for survival and health due to the rapid replication of invading microbes and the delayed action of the adaptive immune system. Antimicrobial peptides are important components of human innate immunity. Over 100 such peptides have been identified in various human tissues. Human cathelicidin LL-37 is best studied, and there has been a growing interest in designing new peptides based on LL-37. This chapter describes the alternative processing of the human cathelicidin precursor, protease digestion, and lab cutting of LL-37. Both a synthetic peptide library and structure-based design are utilized to identify the active regions. Although challenging, the determination of the 3D structure of LL-37 enabled the identification of the core antimicrobial region. The minimal region of LL-37 can be function-dependent. We discuss the design and potential applications of LL-37 into antibacterial, antibiofilm, antiviral, antifungal, immune modulating, and anticancer peptides. LL-37 has been engineered into 17BIPHE2, a stable, selective, and potent antimicrobial, antibiofilm, and anticancer peptide. Both 17BIPHE2 and SAAP-148 can eliminate the ESKAPE pathogens and show topical in vivo antibiofilm efficacy. Also discussed are other application strategies, including peptide formulation, antimicrobial implants, and peptide-inducing factors such as vitamin D and sunlight. Finally, we summarize what we learned from peptide design based on human LL-37.
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16
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Multi-cellular transitional organotypic models to investigate liver fibrosis. Acta Biomater 2018; 82:79-92. [PMID: 30316024 DOI: 10.1016/j.actbio.2018.10.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2018] [Revised: 10/06/2018] [Accepted: 10/09/2018] [Indexed: 12/18/2022]
Abstract
Hepatic fibrosis is the result of wound healing and inflammation resulting in organ dysfunction. Hepatocytes, liver sinusoidal endothelial cells (LSECs), Kupffer cells (KCs), and hepatic stellate cells (HSCs) play critical roles in fibrogenesis. As the liver undergoes fibrosis, there are populations of cells that are healthy, fibrotic as well as those undergoing fibrosis. We investigated how a varying mechanical environment could induce changes in hepatic cells. In this study, a gradient in the mechanical properties of the microenvironment resulted in transitioning phenotypes in hepatic cells. We have designed detachable polyelectrolyte multilayers (PEMs) whose elastic moduli ranged from 21 to 43 kPa to serve as Space of Disse mimics. We assembled novel 3D organotypic liver models comprised of hepatocytes, LSECs, HSCs, KCs, and the Space of Disse mimic. We demonstrate how cells in contact with a mechanical gradient exhibit different properties compared to cells cultured using non-gradient PEMs. Significant differences were observed in HSC and KC proliferation between 3D cultures assembled with gradient and non-gradient PEMs. While HSCs on the stiffer regions of the gradient PEMs expressed both GFAP and α-SMA, cells in cultures assembled with homogeneous 43 kPa multilayers primarily expressed α-SMA. Over an 8-day culture, the elastic modulus in the 21 and 43 kPa regions of the gradient PEMs increased by 1.6 and 3.7-fold, respectively. This was accompanied by a 4-fold increase in hydroxyproline. Such in vitro tissues can be used to investigate the effects of liver fibrosis. STATEMENT OF SIGNIFICANCE: We have assembled a liver model assembled with four major primary hepatic cell types to investigate how a varying mechanical environment induces changes in hepatic cells. In this study, a gradient in the mechanical properties of the microenvironment results in transitioning phenotypes in hepatic cells. Our goal was to investigate the interplay between mechanical properties and a multi-cellular engineered liver tissue. In these models, Kupffer cell proliferation and hepatic stellate cell activation occurred due to mechanical cues and inter-cellular signaling across a distance of 2000 μm. These models are unique, in that, fibrosis was initiated purely through changes to the microenvironment. These models were not exposed to fibrogenic factors nor were the models assembled with cells from fibrotic rats. To the best of our knowledge, these are the first liver models that capture how a gradient microenvironment can result in transitioning cellular phenotypes.
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17
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Wang S, Yan C, Zhang X, Shi D, Chi L, Luo G, Deng J. Antimicrobial peptide modification enhances the gene delivery and bactericidal efficiency of gold nanoparticles for accelerating diabetic wound healing. Biomater Sci 2018; 6:2757-2772. [PMID: 30187036 DOI: 10.1039/c8bm00807h] [Citation(s) in RCA: 93] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Impaired angiogenesis and bacterial infection have increasingly been implicated as the major causes of delayed diabetic wound healing. However, there is currently no effective therapy. Here, we optimized a novel gene delivery system based on antimicrobial peptide (LL37) grafted ultra-small gold nanoparticles (AuNPs@LL37, ∼7 nm) for the topical treatment of diabetic wounds with or without bacterial infection. AuNPs@LL37 combines the advantages of cationic AuNPs that condense DNA with those of antibacterial peptides, which are both highly antibacterial and essential for enhancing cellular and nucleus entry to achieve high gene delivery efficiency. AuNPs@LL37 combined with pro-angiogenic (VEGF) plasmids (AuNPs@LL37/pDNAs) significantly improved the gene transfection efficiency in keratinocytes compared with pristine AuNPs/pDNAs, and showed similar expression to Lipo2000/pDNAs (a well-known highly efficient gene transfection agent). Moreover, our therapeutic depot showed higher antibacterial ability than the free antimicrobial peptides and the cationic AuNPs alone in vitro and in vivo due to synergistic effects. Furthermore, the combined system promoted angiogenesis and inhibited bacterial infection in diabetic wounds, resulting in accelerated wound closure rates, faster re-epithelization, improved granulation tissue formation and high VEGF expression. Finally, our therapeutic depot was highly biocompatible in vitro and in vivo, suggesting its potential as a feasible way to treat chronic diabetic wounds.
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Affiliation(s)
- Song Wang
- Institute of Burn Research, Southwest Hospital, State Key Lab of Trauma, Burn and Combined Injury, Third Military Medical University (Army Medical University), Chongqing 400038, China.
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Orbach SM, Ehrich MF, Rajagopalan P. High-throughput toxicity testing of chemicals and mixtures in organotypic multi-cellular cultures of primary human hepatic cells. Toxicol In Vitro 2018; 51:83-94. [PMID: 29751030 DOI: 10.1016/j.tiv.2018.05.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2017] [Revised: 05/06/2018] [Accepted: 05/07/2018] [Indexed: 02/07/2023]
Abstract
High-throughput screening (HTS) of liver toxicants can bridge the gap in understanding adverse effects of chemicals on humans. Toxicity testing of mixtures is time consuming and expensive, since the number of possible combinations increases exponentially with the number of chemicals. The combination of organotypic culture models (OCMs) and HTS assays can lead to the rapidly evaluation of chemical toxicity in a cost and time-effective manner while prioritizing chemicals that warrant additional investigation. We describe the design, assembly and toxicant response of multi-cellular hepatic organotypic culture models comprised of primary human or rat cells assembled in 96-well plates (denoted as μOCMs). These models were assembled using automated procedures that did not affect hepatocyte function or viability, rendering them ideal for large-scale toxicity evaluations. Rat μOCMs were assembled to obtain insights into deviations from human toxicity. Four test chemicals (acetaminophen, ethanol, isoniazid, and perfluorooctanoic acid) were added to the μOCMs individually or in mixtures. HTS assays were utilized to measure cell death, apoptosis, glutathione depletion, mitochondrial membrane damage, and cytochrome P450 2E1 activity. The μOCMs exhibited increased toxicant sensitivity compared to hepatocyte sandwich cultures. Synergistic and non-synergistic interactions were observed when the toxicants were added as mixtures. Specifically, chemical interactions in the μOCMs were manifested by changes in apoptosis and decreased glutathione. The μOCMs accurately predicted hepatotoxicity for individual and mixtures of toxicants, demonstrating their potential for large-scale toxicity evaluations in the future.
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Affiliation(s)
- Sophia M Orbach
- Department of Chemical Engineering, Virginia Tech, Suite 245 Goodwin Hall, 635 Prices Fork Road, Blacksburg, VA 24061, USA.
| | - Marion F Ehrich
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, 205 Duck Pond Drive, Blacksburg, VA 24061, USA.
| | - Padmavathy Rajagopalan
- Department of Chemical Engineering, Virginia Tech, Suite 245 Goodwin Hall, 635 Prices Fork Road, Blacksburg, VA 24061, USA; ICTAS Center for Systems Biology of Engineered Tissue, Virginia Tech, 333 Kelly Hall, 325 Stanger Street, Blacksburg, VA 24061, USA; School of Biomedical Engineering and Sciences, Virginia Tech, 333 Kelly Hall, 325 Stanger Street, Blacksburg, VA 24061, USA.
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19
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Lozeau LD, Grosha J, Kole D, Prifti F, Dominko T, Camesano TA, Rolle MW. Collagen tethering of synthetic human antimicrobial peptides cathelicidin LL37 and its effects on antimicrobial activity and cytotoxicity. Acta Biomater 2017; 52:9-20. [PMID: 28017866 DOI: 10.1016/j.actbio.2016.12.047] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2016] [Revised: 12/05/2016] [Accepted: 12/21/2016] [Indexed: 12/22/2022]
Abstract
Wound infections, particularly of chronic wounds, pose a substantial challenge for designing antimicrobial dressings that are both effective against pathogens, and do not interfere with wound healing. Due to their broad-spectrum antimicrobial and immunomodulatory activities, naturally-occurring antimicrobial peptides (AMPs) are promising alternative treatments. However, their cytotoxicity at high concentrations and poor stability hinders their clinical use. To mitigate these undesirable properties, we investigated the effects of tethering human AMP cathelicidin LL37 to collagen, one of the main extracellular matrix proteins in wound sites, secreted by fibroblasts, and in commercially-available wound dressings. The active domain of human AMP cathelicidin, LL37, and two chimeric peptides containing LL37 fused to collagen binding domains (derived from collagenase - cCBD-LL37 or fibronectin - fCBD-LL37) were synthesized and adsorbed to PURACOL® type I collagen scaffolds. After 14days, 73%, 81% and 99% of LL37, cCBD-LL37 and fCBD-LL37, respectively, was retained on the scaffolds and demonstrated undiminished antimicrobial activity when challenged with both Gram-positive and Gram-negative bacterial strains. Loaded scaffolds were not cytotoxic to fibroblasts despite retaining peptides at concentrations 24 times higher than the reported cytotoxic concentrations in solution. These findings indicate that biopolymer-tethered AMPs may represent a viable alternative for preventing and treating wound infection while also supporting tissue repair. STATEMENT OF SIGNIFICANCE Over 6.5million people annually in the United States suffer chronic wounds; many will become infected with antibiotic-resistant bacteria. Treatments used to prevent and fight infection are toxic and may hinder wound healing. AMPs are broad-spectrum antimicrobials that also promote healing; however, their instability and toxicity are major challenges. To overcome treatment gaps, we functionalized collagen scaffolds with chimeric antimicrobial peptides (AMPs) with collagen binding domains to create antimicrobial and non-cytotoxic scaffolds that may promote healing. This is the first report of CBD-mediated delivery of AMPs onto collagen scaffolds that demonstrates no cytotoxicity toward fibroblasts. This study also suggests that retention of antimicrobial activity is CBD-dependent, which provides foundations for fundamental studies of CBD-AMP mechanisms and clinical explorations.
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Affiliation(s)
- Lindsay D Lozeau
- Dept. of Chemical Engineering, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, United States
| | - Jonian Grosha
- Dept. of Biomedical Engineering, Politecnico di Milano, Piazza Leonardo da Vinci, 32, 20133 Milan, Italy; Dept. of Biomedical Engineering, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, United States
| | - Denis Kole
- Dept. of Biomedical Engineering, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, United States; Dept. of Biology and Biotechnology, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, United States
| | - Fioleda Prifti
- Dept. of Biomedical Engineering, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, United States; Dept. of Chemistry and Biochemistry, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, United States
| | - Tanja Dominko
- Dept. of Biology and Biotechnology, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, United States; Center for Biomedical Sciences and Engineering, University of Nova Gorica, Vipavska cesta, 5000 Nova Gorica, Slovenia
| | - Terri A Camesano
- Dept. of Chemical Engineering, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, United States
| | - Marsha W Rolle
- Dept. of Biomedical Engineering, Worcester Polytechnic Institute, 100 Institute Road, Worcester, MA 01609, United States.
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Delivery systems for antimicrobial peptides. Adv Colloid Interface Sci 2017; 242:17-34. [PMID: 28159168 DOI: 10.1016/j.cis.2017.01.005] [Citation(s) in RCA: 144] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 01/24/2017] [Accepted: 01/24/2017] [Indexed: 12/18/2022]
Abstract
Due to rapidly increasing resistance development against conventional antibiotics, finding novel approaches for the treatment of infections has emerged as a key health issue. Antimicrobial peptides (AMPs) have attracted interest in this context, and there is by now a considerable literature on the identification such peptides, as well as on their optimization to reach potent antimicrobial and anti-inflammatory effects at simultaneously low toxicity against human cells. In comparison, delivery systems for antimicrobial peptides have attracted considerably less interest. However, such delivery systems are likely to play a key role in the development of potent and safe AMP-based therapeutics, e.g., through reducing chemical or biological degradation of AMPs either in the formulation or after administration, by reducing adverse side-effects, by controlling AMP release rate, by promoting biofilm penetration, or through achieving co-localization with intracellular pathogens. Here, an overview is provided of the current understanding of delivery systems for antimicrobial peptides, with special focus on AMP-carrier interactions, as well as consequences of these interactions for antimicrobial and related biological effects of AMP-containing formulations.
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