The protocol described in this chapter details the synthesis of Desotamides, a class of cyclic hexapeptide antibiotics from Streptomyces species. These peptides, which often include D-amino acids and non-proteogenic amino acids, are challenging to produce using molecular biology techniques. Their synthesis involves loading the first amino acid onto 2-chlorotrityl chloride resin, followed by fluorenylmethyloxycarbonyl (Fmoc) solid phase synthesis of the linear peptide, cleavage of a protected peptide fragment from the resin using mild acidic conditions, and head-to-tail cyclization in solution. These synthetic processes permit the scalable production and engineering of Desotamides and novel-related antimicrobial species, without the limitations of biological synthesis methods.
The increasing demand for multifunctional nanomaterials has highlighted the significance of environmentally sustainable synthesis methods. This study presents an innovative green and efficient approach to the encapsulation of green silver (Ag) nanoparticles with metal oxide of zinc (Zn) to produce ZnO@Ag nanocomposite (NC), employing aqueous neem extract as both a stabilizer and reducing agent. NCs are materials synthesized with two or more components, with at least one component falling in then nanometer scale. Such combined materials bring the properties of both components together, resulting in unique properties distinct from those of individual materials. Thus, this study provides a strong mechanistic approach to the biosynthesis process of nanocomposites and their antibacterial and catalytic activities. The one-pot biosynthesis, performed in an ultrasonicated bath, produced uniformly dispersed nanoparticles in 1 h, representing a quick and efficient way to synthesize nanocomposites. UV-vis spectra revealed a broad absorption peak (320-500 nm), confirming ZnO@Ag integration, while FTIR unveiled neem-derived polyphenolic groups as stabilizers; TEM and HRTEM highlighted spherical nanostructures (25 +/- 3 nm) with crystalline SAED patterns and a bioprotective phytochemical coating. The chemical states and surface composition of the ZnO@Ag nanocomposites were analyzed through XPS. The produced ZnO@Ag NC exhibited remarkable antibacterial effectiveness, producing inhibition zones of 30 and 29 mm against Staphylococcus aureus and Pseudomonas aeruginosa, respectively. Furthermore, the nanocomposite exhibited exceptional catalytic activity, effectively decomposing methylene blue (MB) and methyl orange (MO) dyes by 96 and 93%, respectively. Overall, this study demonstrates an ultrasonic-assisted approach of combining the properties of Ag and Zn metal oxides that integrates exceptional antibacterial and catalytic efficacy while adhering to green chemistry principles. This research identifies ZnO@Ag nanocomposite as a transformative innovation for health and environmental applications, offering a sustainable solution to worldwide issues of antibiotic resistance and pollutant cleanup.
The skin has an important role in regulating homeostasis and protecting the body from endogenous and exogenous microenvironments. Although 3D models for drug discovery have been extensively studied, there is a growing demand for more advanced 3D skin models to enhance skin research. The use of these advanced skin models holds promise across domains such as cosmetics, skin disease treatments, and toxicity testing of new therapeutics. Recent advances include the development of skin-on-a-chip, spheroids, reconstructed skin, organoids, and computational approaches, including quantitative structure-activity relationship (QSAR) and quantitative structure-property relationship (QSPR) research. These innovations are bridging the gap between traditional 2D and advanced 3D models, moving progress from research to clinical applications. In this review, we highlight in vitro and computational skin models with advanced drug discovery for skin-related applications.
Annually, the global production of Fruit and Vegetables (FV) amounts to nine billion tons to satisfy the growing population's needs. However, over one billion metric tons are wasted due to the perishable nature of fruits and vegetables. Various variables, including management, treatment, and insufficient utilization, contribute to the development of trash. Although FV waste is considered unfit for ingestion, it has significant potential for bioactive compounds (BC) that may be used in nutraceuticals and medicines. This review highlights the environmental impact and potential of circular economy generation of FV waste for various applications. The bibliographic keyword analysis of literature is done by showing the trends of keywords, terms used, and the citation chain which helps in the efficient search of literature. Examination of prevalent extraction techniques for bioactive compounds from fruit and vegetable waste underscores the pivotal role of microwave, ultrasonic, supercritical fluid, and enzyme-assisted methodologies, illuminating their respective strengths and limitations. The industrial and forecast potential of bioactive compounds like polyphenols, pectin, and carotenoids, their multifaceted applications in food, pharmaceuticals, cosmetics, and healthcare, and promising significant advancements in functional ingredients and therapeutic formulations are discussed. The necessity of reutilization of FV waste is also reported as transforming and upcycling BC for pharmaceutical and nutraceutical importance. Such innovation will simultaneously aid in the sustainable utilization of FV compounds and the generation of a circular economy which leads to achieving SDG. Notably, the review also reflects a deeper understanding and comprehensive need for future demand and commercialization of BC based on the current acceptance of naturally derived compounds which serve the purpose well of SDG and circular economy.
Vaccine development against group A Streptococcus (GAS) has gained traction in the last decade, fuelled by recognition of the significant worldwide burden of the disease. Several vaccine candidates are currently being evaluated in preclinical and early clinical studies. Here, we investigate two conjugate vaccine candidates that have shown promise in mouse models of infection. Two antigens, the J8 peptide from the conserved C-terminal end of the M protein, and the group A carbohydrate lacking N-acetylglucosamine side chain (ΔGAC) were each conjugated to arginine deiminase (ADI), an anchorless surface protein from GAS. Both conjugate vaccine candidates combined with alum adjuvant were tested in a non-human primate (NHP) model of pharyngeal infection. High antibody titres were detected against J8 and ADI antigens, while high background antibody titres in NHP sera hindered accurate quantification of ΔGAC-specific antibodies. The severity of pharyngitis and tonsillitis signs, as well as the level of GAS colonisation, showed no significant differences in NHPs immunised with either conjugate vaccine candidate compared to NHPs in the negative control group.
Angiotensin-converting enzyme 2 (ACE2) is protective in cardiovascular disease, lung injury and diabetes yet paradoxically underlies our susceptibility to SARs-CoV2 infection and the fatal heart and lung disease it can induce. Furthermore, diabetic patients have chronic, systemic inflammation and altered ACE2 expression resulting in increased risk of severe COVID-19 and the associated mortality. A drug that could increase ACE2 activity and inhibit cellular uptake of severe acute respiratory syndrome coronavirus 2 (SARs-CoV2), thus decrease infection, would be of high relevance to cardiovascular disease, diabetes and SARs-CoV2 infection. While the need for such a drug lead was highlighted over a decade ago receiving over 600 citations,1 to date, no such drugs are available.2 Here, we report the development of a novel ACE2 stimulator, designated '2A'(international PCT filed), which is a 10 amino acid peptide derived from a snake venom, and demonstrate its in vitro and in vivo efficacy against SARs-CoV2 infection and associated lung inflammation. Peptide 2A also provides remarkable protection against glycaemic dysregulation, weight loss and disease severity in a mouse model of type 1 diabetes. No untoward effects of 2A were observed in these pre-clinical models suggesting its strong clinical translation potential.
Sortase A (SrtA) is an enzyme which attaches proteins, including virulence factors, to bacterial cell walls. It is a potential target for developing anti-virulence agents against pathogenic and antimicrobial resistant bacteria. This study aimed to engineer 𝛽-lactoglobulin protein nanoparticles (PNPs) for encapsulating safe and inexpensive natural SrtA inhibitors (SrtAIs; trans-chalcone (TC), curcumin (CUR), quercetin (QC), and berberine (BR)) to improve their poor aqueous dispersibility, to screen for synergy with antimicrobial peptides (AMPs), and to reduce the cost, dose, and toxicity of AMPs. Minimum inhibitory concentration (MIC), checkerboard synergy, and cell viability assays were performed for SrtAI PNPs against Gram-positive (methicillin-sensitive and -resistant S. aureus) and Gram-negative (E. coli, P. aeruginosa) bacteria alone and combined with leading AMPs (pexiganan, indolicidin, and a mastoparan derivative). Each SrtAI PNP inhibited Gram-positive (MIC: 62.5–125 µg/mL) and Gram-negative (MIC: 31.3–500 µg/mL) bacterial growth. TC PNPs with pexiganan demonstrated synergy against each bacteria, while BR PNPs with pexiganan or indolicidin provided synergy towards S. aureus. Each SrtAI PNP inhibited SrtA (IC50: 25.0–81.8 µg/mL), and did not affect HEK-293 cell viability at their MIC or optimal synergistic concentrations with AMPs. Overall, this study provides a safe nanoplatform for enhancing antimicrobial synergy to develop treatments for superbug infections.
The CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 genome editing system has been a major technological breakthrough that has brought revolutionary changes to genome editing for therapeutic and diagnostic purposes and precision medicine. With the advent of the CRISPR/Cas9 system, one of the critical limiting factors has been the safe and efficient delivery of this system to cells or tissues of interest. Several approaches have been investigated to find delivery systems that can attain tissue-targeted delivery, lowering the chances of off-target editing. While viral vectors have shown promise for in vitro, in vivo and ex vivo delivery of CRISPR/Cas9, their further clinical applications have been restricted due to shortcomings including limited cargo packaging capacity, difficulties with large-scale production, immunogenicity and insertional mutagenesis. Rapid progress in nonviral delivery vectors, including the use of lipid, polymer, peptides, and inorganic nanoparticle-based delivery systems, has established nonviral delivery approaches as a viable alternative to viral vectors. This review will introduce the molecular mechanisms of the CRISPR/Cas9 gene editing system, current strategies for delivering CRISPR/Cas9-based tools, an overview of strategies for overcoming off-target genome editing, and approaches for improving genome targeting and tissue targeting. We will also highlight current developments and recent clinical trials for the delivery of CRISPR/ Cas9. Finally, future directions for overcoming the limitations and adaptation of this technology for clinical trials will be discussed.
This study aimed to develop synergistic therapies to treat superbug infections through the encapsulation of sortase A inhibitors (SrtAIs; trans-chalcone (TC), curcumin (CUR), quercetin (QC), or berberine chloride (BR)) into MCM-41 mesoporous silica nanoparticles (MSNs) or a phosphonate-modified analogue (MCM-41-PO3−) to overcome their poor aqueous solubility. A resazurin-modified minimum inhibitory concentration (MIC) and checkerboard assays, to measure SrtAI synergy in combination with leading antimicrobial peptides (AMPs; pexiganan (PEX), indolicidin (INDO), and [I5, R8] mastoparan (MASTO)), were determined against methicillin-sensitive (MSSA) and methicillin-resistant (MRSA) Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. The results demonstrated that the MCM-41 and MCM-41-PO3− formulations significantly improved the aqueous solubility of each SrtAI. The MICs for SrtAI/MCM-41-PO3− formulations were lower compared to the SrtAI/MCM-41 formulations against tested bacterial strains, except for the cases of BR/MCM-41 and QC/MCM-41 against P. aeruginosa. Furthermore, the following combinations demonstrated synergy: PEX with TC/MCM-41 (against all strains) or TC/MCM-41-PO3− (against all strains except P. aeruginosa); PEX with BR/MCM-41 or BR/MCM-41-PO3− (against MSSA and MRSA); INDO with QC/MCM-41 or QC/MCM-41-PO3− (against MRSA); and MASTO with CUR/MCM-41 (against E. coli). These combinations also reduced each components’ toxicity against human embryonic kidney cells. In conclusion, MCM-41 MSNs provide a platform to enhance SrtAI solubility and demonstrated antimicrobial synergy with AMPs and reduced toxicity, providing novel superbug treatment opportunities.
Glucagon-like peptide-1 GLP-1 is a gut-derived peptide secreted from pancreatic β-cells that reduces blood glucose levels and body weight; however, native GLP-1 (GLP-1(7-36)-NH2 and GLP-1(7-37)) have short in vivo circulation half-lives (∼2 min) due to proteolytic degradation and rapid renal clearance due to its low molecular weight (MW; 3297.7 Da). This study aimed to improve the proteolytic stability and delivery properties of glucagon-like peptide-1 (GLP-1) through modifications that form nanostructures. For this purpose, N- (NtG) and C-terminal (CtG), and Lys26 side chain (K26G) alkyne-modified GLP-1 analogues were conjugated to an azide-modified lipidic peptide (L) to give N-L, C-L, and K-26-L, respectively; or CtG was conjugated with a fibrilizing self-assembling peptide (SAP) (AEAEAKAK)3 to yield C-S, using copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC). N-L demonstrated the best serum stability (t1/2 > 48 h) compared to K-26-L (44 h), C-L (20 h), C-S (27 h), and the parental GLP-1(7-36;A8G)-NH2 (A8G) (19 h) peptides. Each conjugate demonstrated subnanomolar hGLP-1RA potency, and none demonstrated toxicity toward PC-3 cells at concentrations up to 1 μM. Each analogue was observed by transmission electron microscopy to form fibrils in solution. K-26-L demonstrated among the best human serum stability (t1/2 = 44 h) and similar hGLP-1RA potency (EC50 48 pM) to C-S. In conclusion, this study provided an alternative to lipid modification, i.e., fibrillizing peptides, that could improve pharmacokinetic parameters of GLP-1.
Atherosclerosis, the major underlying pathology of cardiovascular disease, commences with the binding and trapping of lipids on modified proteoglycans, with hyperelongated glycosaminoglycan chains. Transforming growth factor (TGF)-β stimulates glycosaminoglycan elongation in vascular smooth muscle cells. We have recently shown that this TGF-β signaling pathway involves reactive oxygen species (ROS). YY-11 is a dodecapeptide derived from camel milk and it has antioxidant activity. We have investigated the role of YY-11 in blocking ROS signaling and downstream atherogenic responses. YY-11 inhibited TGF-β stimulated ROS production and inhibited the expression of genes for glycosaminoglycan chain elongation as a component of an in vitro model of atherosclerosis. This study provides a biochemical mechanism for the role of camel milk as a potential nutritional product to contribute to the worldwide amelioration of cardiovascular disease. PRACTICAL APPLICATIONS: The identification of readily accessible foods with antioxidant properties would provide a convenient and cost-effective approach community wide reducing oxidative stress induced pathologies such as atherosclerosis. We demonstrate that camel milk-derived peptide is an antioxidant that can inhibit growth factor-mediated proteoglycan modification in vitro. As proteoglycan modification is being recognized as one of the earliest atherogenic responses, these data support the notion of camel milk as a suitable nutritional product to contribute to the prevention of early stage of atherosclerosis development.
Increasing antimicrobial resistance is a major global health concern. Conventional antibiotics apply selection pressures, which promote the accumulation of resistant microbes. Anti-virulence strategies, in contrast, are less potent antimicrobials, but are less likely to select for resistance, can be combined with existing antibiotics to improve their activity, and in some cases can overcome antimicrobial resistance towards other antimicrobials. Sortase A inhibitors (SrtAIs) represent an exciting example of this class; however, many reported examples demonstrate poor water solubility, which complicates their biological assessment and activity. This includes reports that use antimicrobial concentrations of organic solvents or conditions that fail to solubilise these compounds for minimal inhibitory concentration (MIC) assessments. Herein, we report the first study to optimise screening processes for a library of prospective SrtAIs (trans-chalcone (TC), berberine (BR), curcumin (CUR), and quercetin (QC)), including comparative assessment of the effects of various co-solvent concentrations, along with comparative assessment of their antimicrobial activities against multiple disease relevant bacterial strains (methicillin-sensitive and resistant S. aureus, E. coli, and P. aeruginosa), inhibition of the sortase A enzyme, and toxicity towards mammalian cells (HEK-293), using these optimised conditions. Optimal solubility with minimal effect on bacterial viability was observed in the presence of 5% (v/v) dimethyl sulfoxide (DMSO)-Mueller-Hinton Broth. Three antimicrobial susceptibility tests (broth microdilution, agar dilution, and disk diffusion) were assessed for their ability to accurately determine minimal inhibitory concentration (MIC) data for each SrtAI. Broth microdilution and agar dilution were both effective; however, the broth microdilution assay required the addition of a colorimetric metabolic indicator (resazurin) to enable simple and reliable MIC determination due to the development of precipitants over time. In contrast, disk diffusion did not provide reliable zone of inhibition data. Identical MIC data was observed with methicillin-sensitive and -resistant S. aureus (MRSA; ATCC43300), with lower potency activity against E. coli and P. aeruginosa. Under these conditions, TC and CUR demonstrated significant toxicity towards human embryonic kidney (HEK-293) cells, with QC showing less toxicity and BR limited-to-no toxicity at its MIC. Overall, the findings of this work provide optimised processes, which will prove useful for the study of other poorly soluble antimicrobial agents and SrtAIs. The obtained data suggests that BR should be considered in preference to the other SrtAIs for the development of new antimicrobial formulations, based on its superior antimicrobial and SrtA inhibition potency, and greatly reduced toxicity.
Virulence factor, sortase A (SrtA), has crucial roles in the pathogenesis of Gram-positive superbugs. SrtA is a bacterial cell membrane enzyme that anchors crucial virulence factors to the cell wall surface of Gram-positive bacteria. SrtA is not necessary for bacterial growth and viability and is conveniently accessible in the cell membrane; therefore, it is an ideal target for antivirulence drug development. In this review, we focus on antimicrobial resistance (AMR)-expressing bacteria and SrtA as a potential target for overcoming AMR. The mechanism of action of SrtA and its inhibition by various types of inhibitors, such as synthetic small molecules, peptides, and natural products, are provided. Future SrtA research perspectives for alternative drug development to antibiotics are also proposed.
Neutralising antibodies (NAbs), caused by past adeno-associated virus (AAV) infection, represent a critical challenge for AAV-mediated gene therapy, with even low NAb titres capable of inhibiting gene transfer, however in protein-rich environments such as the vitreous it is expected that other constituents could also interact with the transduction process. Inhibition of AAV2/2, AAV2/5, AAV2/6 and AAV2/8 transduction by human vitreous humour (VH) obtained from 80 post-mortem eye cups was investigated in this report, with clinically relevant vitreous dilutions as low as 1:2. Unexpectedly, the highest prevalence of inhibition of transduction was observed against AAV2/6, with 66% of tested samples displaying neutralisation at a 1:2 VH dilution. Only two samples showed inhibition of AAV2/8, indicating this serotype is an attractive vector for use in non-vitrectomised eyes of unscreened individuals. Levels of anti-AAV NAbs observed in the VH were much lower than previously observed in serum of a similar Australian population. Among ten tested eye cup pairs, we observed only small variation in anti-AAV NAbs levels between the left and right eye cups. Interaction with 1:2 diluted VH had an augmentation effect on AAV2/8 transduction (p = 0.004), a phenomenon which was not due to albumin or transferrin and which, if developed, might benefit the use of AAV2/8 in clinical settings.
Subunit vaccines composed of protein antigens covalently attached to Toll-like receptor (TLR) agonists elicit superior immune responses compared to mixtures of antigens and TLR agonists. Among different conjugation approaches, enzyme-mediated ligation is one of the few that provides an opportunity for the generation of homogeneous, molecularly defined products in which protein antigens are maintained with native structures, which is most critical to elicit protective immune responses upon vaccination. Four highly conserved protein antigens from Group A Streptococcus (GAS) have the potential to be safe and efficacious vaccine candidates. After a TLR2 agonist fibroblast-stimulating lipopeptide-1 (FSL-1) was successfully attached onto each antigen using sortase A and techniques for their purification were developed, a combination vaccine containing interleukin 8 (IL-8) protease (Streptococcus pyogenes cell envelope proteinase [SpyCEP]), Group A Streptococcal C5a peptidase (SCPA), anchorless virulence factor arginine deiminase (ADI), and trigger factor (TF)-TLR2 conjugates was produced. This combination was assessed for immunity in mice and compared with mixtures of the four antigens with FSL-1 or alum. High titer antigen-specific IgG antibodies were detected from all vaccine groups, with antibodies elicited from FSL-1 conjugates around 10-fold higher compared to the FSL-1 mixture group. Furthermore, the FSL-1 conjugates afforded a more balanced TH1/TH2 immune response than the alum-adjuvanted group, suggesting that this combination vaccine represents a promising candidate for the prevention of GAS diseases. Thus, we established a conjugation platform that allows for the production of defined, site-specific antigen-adjuvant conjugates, which maintain the native three-dimensional structure of antigens and can be potentially applied to a variety of protein antigens.
This study aimed to develop and optimize chemistries to produce alkyne-modified glucagon-like peptide-1(7-36)-amide (GLP-1(7-36)-NH2) libraries, which could be rapidly and efficiently conjugated to other components and screened to identify compounds with the best drug delivery properties, as potential treatments for type 2 diabetes or obesity. For this purpose, the Lys26 (K26) side-chain, and the amino (N)-and carboxy (C)-termini of a dipeptidyl peptidase 4 (DPPIV)-resistant GLP-1 sequence (GLP-1(7-36; A8G)-NH2), were modified with an alkyne (4-pentynoic acid or propiolic acid). These analogs were characterized with respect to human GLP-1 receptor (hGLP-1R) agonist activity, effects on cell viability and human serum stability, revealing that these modifications maintained low (N-terminal; EC50 1.5 x 10(-9) M) to subnanomolar (C-terminal and K26, similar to 4 x 10(-10) M) agonist activity toward hGLP-1, had no effect on cell viability, and for the N-terminal and K26 modifications, increased human serum proteolytic stability (t(1/2) > 24 h). Copper-catalyzed azide-alkyne cycloaddition (CuAAC) reaction conditions were investigated using the C-terminal modified GLP-1 analog and an azide-modified model lipid peptide, with respect to the effects of altering the azide/alkyne ratio, cosolvents, temperature, reducing agents, Cu(I)-stabilizing ligand, copper source, and the concentrations of reagents/reactants, in order to identify general conditions that provide fast reactions and high yields. A 1:2 azide-alkyne (lipid:GLP-1 peptide) and 4:1 sodium ascorbate/copper sulfate molar ratio in 65% v/v DMSO-water at room temperature, in the absence of Cu(I)-stabilizing ligands (THPTA or L-histidine) and buffers (phosphate, pH 7), provided the best yields. This work reports a library of characterized GLP-1 analogs and chemistries for their attachment to other species, providing useful tools to improve GLP-1 delivery and pharmacology (e.g., through conjugation to other species that lower blood glucose, increase the duration of action, or enable delivery via a nonparenteral route).
aAustralian Infectious Diseases Research Centre, The University of Queensland, St. Lucia, QLD, Australia bSchool of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD, Australia cEmory Vaccine Center, Emory University, Atlanta, Georgia, USA dYerkes National Primate Research Center, Emory University, Atlanta, Georgia, USA eGreat Ormond Street Institute of Child Health, University College London, London, United Kingdom fPeter Doherty Institute, University of Melbourne, Parkville, VIC, Australia gSchool of Pharmacy, The University of Queensland, St. Lucia, QLD, Australia hInstitute for Glycomics, Griffith University, Gold Coast, QLD, Australia iAustralian Infectious Diseases Research Centre, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia jDivision of Host-Microbe Systems and Therapeutics, Department of Pediatrics, University of California—San Diego, La Jolla, California, USA
Protein antigens are, in general, weakly immunogenic, and therefore require co-delivery with adjuvants to stimulate potent immune responses. The fusion of (poly)peptide antigens to immunostimulatory adjuvants (e.g. Toll-like receptor (TLR) agonists) has been demonstrated to greatly improve vaccine potency compared to mixtures of antigen and adjuvant. Chemical approaches, to enable the rapid, site-specific and high-yielding linkage of TLR2 ligands to recombinant protein antigens, have been previously optimized. These approaches require the use of denaturing conditions to ensure high reaction yields, which limits their application, as maintenance of native protein folding is necessary to elicit antibodies against conformational epitopes. Here, this work aimed to optimize an alternative method, to ensure the efficient bioconjugation of TLR2 ligands onto folded protein antigens. An enzyme-mediated approach, using Staphylococcus aureus sortase A (or a penta mutant with enhanced efficiency), was optimized for reaction yield and time, as well as enzyme type and amount. This approach enabled the site-specific conjugation of the TLR2-agonist fibroblast-stimulating lipopeptide-1 (FSL-1) onto a model group A Streptococcus (GAS) recombinant polytope antigen under conditions that maintain protein folding, yielding a homogeneous, molecularly-defined product, with ligation yields as high as 90%. Following intramuscular (IM) administration of the ligation product to humanized plasminogen AlbPLG1 mice, high-titer, antigen-specific IgG antibodies were observed, which conferred protection against subcutaneous challenge with GAS strain 5448. In comparison, mixtures of the GAS antigen with aluminum hydroxide or FSL-1 failed to provide protection, with the FSL-1 mixture yielding ~1000-fold lower antigen-specific IgG antibody titers, and the mixture with alum yielding a Th2-biased response compared to the more balanced Th1/Th2 responses observed with the FSL-1 conjugate. Overall, a FSL-1 bioconjugation method for the efficient production of antigen-TLR2 agonist conjugates, which maintain protein folding, was produced, with broad utility for the development of self-adjuvanting vaccines against subunit protein antigens.
Aim: To develop albendazole (ABZ)-loaded bombesin(6-14) (BBN(6-14)) functionalized liposomes for targeting GRPR to enhance delivery to cancer cells. Materials & methods: ABZ-loaded liposomes were formulated using supercritical CO2 technology; functionalized with a GRPR-targeted lipid-anchored BBN(6-14) peptide; and evaluated for effects on cell viability, particle size and targeted cell uptake. Results: BBN(6-14)-coated ABZ liposomes decreased cell viability compared with nonfunctionalized ABZ liposomes. The level of GRPR expression positively correlated with intracellular uptake and decreased cell viability. The reduced cell viability, higher cell uptake and GRPR expression were observed in the order PC-3 > Caco-2 > HepG2 cells. Conclusion: BBN(6-14)-functionalized ABZ liposomes showed enhanced reduction in cell viability compared with nonfunctionalized ABZ liposomes.