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1.
Adv Healthc Mater ; : e2401157, 2024 Aug 29.
Article in English | MEDLINE | ID: mdl-39210641

ABSTRACT

Fungal infections can lead to debilitating consequences if they are not treated effectively. Antifungal drugs used to treat these infections can be toxic and overuse contributes to growing antifungal resistance. Candida spp., particularly C. albicans, are implicated in a majority of these infections. Virulent C. albicans produce secreted aspartic proteases (Saps) that aid in pathogen tissue invasion and proliferation at an infected site. Here, fungi-responsive hydrogels are developed that degrade in the presence of Saps to provide a triggered release of encapsulated liposomal antifungals. The hydrogel backbone incorporates a Sap-cleavable peptide sequence enabling Sap-responsive degradation. Hydrogels are found to effectively degrade in the presence of Saps extracted from C. albicans. Encapsulated liposomal antifungals show similar release kinetics as hydrogel degradation products in the presence of Saps, supporting a degradation-dependent release mechanism. Antifungal liposome-loaded responsive hydrogels exhibit successful eradication of C. albicans cultures and remain stable in sterile murine wound fluid. Finally, no significant cytotoxicity is observed for murine fibroblast cells and red blood cells exposed to hydrogel degradation products. These fungi-responsive hydrogels have the potential to be used for local, on-demand delivery of antifungal drugs, for effective treatment of fungal infections while helping to limit unnecessary exposure to these therapeutics.

2.
Pharmaceutics ; 16(3)2024 Feb 20.
Article in English | MEDLINE | ID: mdl-38543192

ABSTRACT

Candida albicans can cause various types of oral infections, mainly associated with denture stomatitis. Conventional therapy has been linked to high recurrence, toxicity, and fungal resistance, necessitating the search for new drugs and delivery systems. In this study, caffeic acid phenethyl ester (CAPE) and gellan gum (GG) were studied as an antifungal agent and carrier system, respectively. First, we observed that different GG formulations (0.6 to 1.0% wt/vol) were able to incorporate and release CAPE, reaching a controlled and prolonged release over 180 min at 1.0% of GG. CAPE-GG formulations exhibited antifungal activity at CAPE concentrations ranging from 128 to >512 µg/mL. Furthermore, CAPE-GG formulations significantly decreased the fungal viability of C. albicans biofilms at short times (12 h), mainly at 1.0% of GG (p < 0.001). C. albicans protease activity was also reduced after 12 h of treatment with CAPE-GG formulations (p < 0.001). Importantly, CAPE was not cytotoxic to human keratinocytes, and CAPE-GG formulations at 1.0% decreased the fungal burden (p = 0.0087) and suppressed inflammation in a rat model of denture stomatitis. Altogether, these results indicate that GG is a promising delivery system for CAPE, showing effective activity against C. albicans and potential to be used in the treatment of denture stomatitis.

3.
ACS Infect Dis ; 9(10): 1949-1963, 2023 10 13.
Article in English | MEDLINE | ID: mdl-37646612

ABSTRACT

Methicillin-resistant Staphylococcus aureus (MRSA) infections are some of the most common antibiotic-resistant infections, often exacerbated by the formation of biofilms. Here, we evaluated six compounds, three common antibiotics used against MRSA and three antibiofilm compounds, in nine combinations to investigate the mechanisms of synergistic eradication of MRSA biofilms. Using metabolic assessment, colony enumeration, confocal fluorescence microscopy, and scanning electron microscopy, we identified two promising combinations of antibiotics with antibiofilm agents against preformed MRSA biofilms. The broad-spectrum protease, proteinase K, and membrane-targeting antibiotic, daptomycin, worked in synergy against MRSA biofilms by manipulating the protein content, increasing access to the cell membrane of biofilm bacteria. We also found that the combination of cationic peptide, IDR-1018, with the cell wall cross-linking inhibitor, vancomycin, exhibited synergy against MRSA biofilms by causing bacterial damage and preventing repair. Our findings identify synergistic combinations of antibiotics and antibiofilm agents, providing insight into mechanisms that may be explored further for the development of effective treatments against MRSA biofilm.


Subject(s)
Anti-Bacterial Agents , Methicillin-Resistant Staphylococcus aureus , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Microbial Sensitivity Tests , Vancomycin/pharmacology , Biofilms
4.
Front Cell Infect Microbiol ; 13: 1135942, 2023.
Article in English | MEDLINE | ID: mdl-37313344

ABSTRACT

Microbe entry through catheter ports can lead to biofilm accumulation and complications from catheter-related bloodstream infection and ultimately require antimicrobial treatment and catheter replacement. Although strides have been made with microbial prevention by applying standardized antiseptic techniques during catheter implantation, both bacterial and fungal microbes can present health risks to already sick individuals. To reduce microbial adhesion, murine and human catheters were coated with polyurethane and auranofin using a dip coating method and compared to non-coated materials. Upon passage of fluid through the coated material in vitro, flow dynamics were not impacted. The unique antimicrobial properties of the coating material auranofin has shown inhibitory activity against bacteria such as Staphylococcus aureus and fungi such as Candida albicans. Auranofin coating on catheters at 10mg/mL reduced C. albicans accumulation in vitro from 2.0 x 108 to 7.8 x 105 CFU for mouse catheters and from 1.6 x 107 to 2.8 x 106 for human catheters, showing an impact to mature biofilms. Assessment of a dual microbe biofilm on auranofin-coated catheters resulted in a 2-log reduction in S. aureus and a 3-log reduction in C. albicans compared to uncoated catheters. In vivo assessment in a murine subcutaneous model demonstrated that catheters coated with 10 mg/mL auranofin reduced independent S. aureus and C. albicans accumulation by 4-log and 1-log, respectively, compared to non-coated catheters. In conclusion, the auranofin-coated catheters demonstrate proficiency at inhibiting multiple pathogens by decreasing S. aureus and C. albicans biofilm accumulation.


Subject(s)
Auranofin , Staphylococcus aureus , Humans , Animals , Mice , Auranofin/pharmacology , Bacteria , Biofilms , Candida albicans , Catheters
5.
J Biomed Mater Res A ; 111(5): 644-659, 2023 05.
Article in English | MEDLINE | ID: mdl-36740998

ABSTRACT

Liposomes are lipid-based nanoparticles that have been used to deliver encapsulated drugs for a variety of applications, including treatment of life-threatening fungal infections. By understanding the effect of composition on liposome interactions with both fungal and mammalian cells, new effective antifungal liposomes can be developed. In this study, we investigated the impact of lipid saturation and cholesterol content on fungal and mammalian cell interactions with liposomes. We used three phospholipids with different saturation levels (saturated hydrogenated soy phosphatidylcholine (HSPC), mono-unsaturated 1-palmitoyl-2-oleoyl-glycero-3-phosphocholine (POPC), and di-unsaturated 1-palmitoyl-2-linoleoyl-sn-glycero-3-phosphocholine (PLPC)) and cholesterol concentrations ranging from 15% to 40% (w/w) in our liposome formulations. Using flow cytometry, >80% of Candida albicans SC5314 cells were found to interact with all liposome formulations developed, while >50% of clinical isolates tested exhibited interaction with these liposomes. In contrast, POPC-containing formulations exhibited low levels of interaction with murine fibroblasts and human umbilical vein endothelial cells (<30%), while HSPC and PLPC formulations had >50% and >80% interaction, respectively. Further, PLPC formulations caused a significant decrease in mammalian cell viability. Formulations that resulted in low levels of mammalian cell interaction, minimal cytotoxicity, and high levels of fungal cell interaction were then used to encapsulate the antifungal drug, amphotericin B. These liposomes eradicated planktonic C. albicans at drug concentrations lower than free drug, potentially due to the high levels of liposome-C. albicans interaction. Overall, this study provides new insights into the design of liposome formulations towards the development of new antifungal therapeutics.


Subject(s)
Antifungal Agents , Liposomes , Animals , Humans , Mice , Antifungal Agents/pharmacology , Endothelial Cells , Phospholipids , Cholesterol , Phosphatidylcholines , Mammals
6.
ACS Appl Mater Interfaces ; 14(24): 27538-27550, 2022 Jun 22.
Article in English | MEDLINE | ID: mdl-35675049

ABSTRACT

Antibiotic resistance is a growing public health threat that complicates the treatment of infections. ß-Lactamase enzymes, which hydrolyze the ß-lactam ring present in many common antibiotics, are a major cause of this resistance and are produced by a broad range of bacterial pathogens. Here, we developed hydrogels that degrade specifically in the presence of ß-lactamases and ß-lactamase-producing bacteria as a platform for bacteria-triggered drug delivery. A maleimide-functionalized ß-lactamase-cleavable cephalosporin was used as a crosslinker in the fabrication of hydrogels through end-crosslinked polymerization with multiarm thiol-terminated poly(ethylene glycol) macromers via Michael-type addition. We demonstrated that only hydrogels containing the responsive crosslinker were degraded by ß-lactamases and ß-lactamase-producing bacteria in vitro and in an ex vivo porcine skin infection model. Fluorescent polystyrene nanoparticles, encapsulated in the hydrogels as model cargo, were released at rates that closely tracked hydrogel wet mass loss, confirming ß-lactamase-triggered controlled cargo release. Nonresponsive hydrogels, lacking the ß-lactam crosslinker, remained stable in the presence of ß-lactamases and ß-lactamase-producing bacteria and exhibited no change in mass or nanoparticle release. Furthermore, the responsive hydrogels remained stable in non-ß-lactamase enzymes, including collagenases and lipases. These hydrogels have the potential to be used as a bacteria-triggered drug delivery system to control unnecessary exposure to encapsulated antimicrobials, which can provide effective infection treatment without exacerbating resistance.


Subject(s)
Hydrogels , beta-Lactamases , Animals , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Bacteria , Drug Delivery Systems , Hydrogels/pharmacology , Swine , beta-Lactams/pharmacology
7.
Biomater Sci ; 10(11): 2831-2843, 2022 May 31.
Article in English | MEDLINE | ID: mdl-35441624

ABSTRACT

Biofilm infections are common and can be extremely difficult to treat. Nanoparticles that respond to multiple bacterial stimuli have the potential to successfully prevent and eradicate biofilms. Here, we developed a hyaluronic acid and chitosan coated, antibiotic loaded gelatin nanoparticle, which can undergo hyaluronidase- and gelatinase-mediated degradation regulated by chitosan protonation and swelling in the acidic biofilm microenvironment. We examined the antibiofilm properties of these nanoparticles using a Gram-negative biofilm forming pathogenic bacteria, Vibrio vulnificus. Non-drug loaded responsive nanoparticle formulations exhibited excellent biofilm penetration and retention in preformed V. vulnificus biofilms. Drug loaded formulations were found to exhibit excellent biofilm eradication efficacy, eliminating the biofilm matrix and effectively causing bacterial cell death, which was not observed for treatment with free drug at equivalent concentrations. Overall, these multi-stimuli-responsive nanoparticles have the potential to provide effective and efficient antibiofilm treatment.


Subject(s)
Chitosan , Nanoparticles , Anti-Bacterial Agents/pharmacology , Bacteria , Biofilms , Biopolymers/pharmacology , Chitosan/pharmacology
8.
Annu Rev Biomed Eng ; 24: 111-135, 2022 06 06.
Article in English | MEDLINE | ID: mdl-35231178

ABSTRACT

Uncontrolled bleeding is a major problem in trauma and emergency medicine. While materials for trauma applications would certainly find utility in traditional surgical settings, the unique environment of emergency medicine introduces additional design considerations, including the need for materials that are easily deployed in austere environments. Ideally, these materials would be available off the shelf, could be easily transported, and would be able to be stored at room temperature for some amount of time. Both natural and synthetic materials have been explored for the development of hemostatic materials. This review article provides an overview of classes of materials used for topical hemostats and newer developments in the area of injectable hemostats for use in emergency medicine.


Subject(s)
Biocompatible Materials , Hemostatics , Hemorrhage , Hemostasis , Humans
9.
ACS Appl Bio Mater ; 5(5): 1890-1900, 2022 05 16.
Article in English | MEDLINE | ID: mdl-35199983

ABSTRACT

Human mesenchymal stem cells (HMSCs) are important for cell-based therapies. However, the success of HMSC therapy requires large-scale in vitro expansion of these multipotent cells. The traditional expansion of HMSCs on tissue-culture-treated stiff polystyrene induces significant changes in their shape, multipotency, and secretome, leading to early senescence and subdued paracrine activity. To enhance their therapeutic potential, here, we have developed two-dimensional soft hydrogels with imprinted microscale aligned grooves for use as HMSC culture substrates. We showed that, depending on the dimensions of the topographical features, these substrates led to lower cellular spreading and cytoskeletal tension, maintaining multipotency and osteogenic and adipogenic differentiate potential, while lowering cellular senescence. We also observed a greater capacity of HMSCs to produce anti-inflammatory cytokines after short-term priming on these hydrogel substrates. Overall, these soft hydrogels with unique surface topography have shown great promise as in vitro culture substrates to maximize the therapeutic potential of HMSCs.


Subject(s)
Hydrogels , Mesenchymal Stem Cells , Adipogenesis , Cellular Senescence , Humans , Hydrogels/metabolism , Osteogenesis
10.
Bioconjug Chem ; 33(2): 263-271, 2022 02 16.
Article in English | MEDLINE | ID: mdl-35107252

ABSTRACT

Bioorthogonal click chemistry, first introduced in the early 2000s, has become one of the most widely used approaches for designing advanced biomaterials for applications in tissue engineering and regenerative medicine, due to the selectivity and biocompatibility of the associated reactants and reaction conditions. In this review, we present recent advances in utilizing bioorthogonal click chemistry for the development of three-dimensional, biocompatible scaffolds and cell-encapsulated biomaterials. Additionally, we highlight recent examples using these approaches for biomedical applications including drug delivery, imaging, and cell therapy and discuss their potential as next generation biomaterials.


Subject(s)
Click Chemistry , Tissue Engineering , Biocompatible Materials , Click Chemistry/methods , Drug Delivery Systems/methods , Regenerative Medicine , Tissue Engineering/methods
11.
J Vis Exp ; (174)2021 08 03.
Article in English | MEDLINE | ID: mdl-34424234

ABSTRACT

Model cell membranes are a useful screening tool with applications ranging from early drug discovery to toxicity studies. The cell membrane is a crucial protective barrier for all cell types, separating the internal cellular components from the extracellular environment. These membranes are composed largely of a lipid bilayer, which contains outer hydrophilic head groups and inner hydrophobic tail groups, along with various proteins and cholesterol. The composition and structure of the lipids themselves play a crucial role in regulating biological function, including interactions between cells and the cellular microenvironment, which may contain pharmaceuticals, biological toxins, and environmental toxicants. In this study, methods to formulate uni-lipid and multi-lipid supported and suspended cell mimicking lipid bilayers are described. Previously, uni-lipid phosphatidylcholine (PC) lipid bilayers as well as multi-lipid placental trophoblast-inspired lipid bilayers were developed for use in understanding molecular interactions. Here, methods for achieving both types of bilayer models will be presented. For cell mimicking multi-lipid bilayers, the desired lipid composition is first determined via lipid extraction from primary cells or cell lines followed by liquid chromatography-mass spectrometry (LC-MS). Using this composition, lipid vesicles are fabricated using a thin-film hydration and extrusion method and their hydrodynamic diameter and zeta potential are characterized. Supported and suspended lipid bilayers can then be formed using quartz crystal microbalance with dissipation monitoring (QCM-D) and on a porous membrane for use in a parallel artificial membrane permeability assay (PAMPA), respectively. The representative results highlight the reproducibility and versatility of in vitro cell membrane lipid bilayer models. The methods presented can aid in rapid, facile assessment of the interaction mechanisms, such as permeation, adsorption, and embedment, of various molecules and macromolecules with a cell membrane, helping in the screening of drug candidates and prediction of potential cellular toxicity.


Subject(s)
Lipid Bilayers , Placenta , Female , Humans , Phosphatidylcholines , Pregnancy , Quartz Crystal Microbalance Techniques , Reproducibility of Results
12.
ACS Infect Dis ; 7(4): 695-720, 2021 04 09.
Article in English | MEDLINE | ID: mdl-33733747

ABSTRACT

Bacterial infections are a major threat to human health, exacerbated by increasing antibiotic resistance. These infections can result in tremendous morbidity and mortality, emphasizing the need to identify and treat pathogenic bacteria quickly and effectively. Recent developments in detection methods have focused on electrochemical, optical, and mass-based biosensors. Advances in these systems include implementing multifunctional materials, microfluidic sampling, and portable data-processing to improve sensitivity, specificity, and ease of operation. Concurrently, advances in antibacterial treatment have largely focused on targeted and responsive delivery for both antibiotics and antibiotic alternatives. Antibiotic alternatives described here include repurposed drugs, antimicrobial peptides and polymers, nucleic acids, small molecules, living systems, and bacteriophages. Finally, closed-loop therapies are combining advances in the fields of both detection and treatment. This review provides a comprehensive summary of the current trends in detection and treatment systems for bacterial infections.


Subject(s)
Bacterial Infections , Biosensing Techniques , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Bacteria , Bacterial Infections/diagnosis , Bacterial Infections/drug therapy , Drug Resistance, Microbial , Humans
13.
Ann Biomed Eng ; 49(9): 2214-2227, 2021 Sep.
Article in English | MEDLINE | ID: mdl-33686620

ABSTRACT

Placental trophoblast cells present in cervical samples have great potential towards non-invasive prenatal testing. However, cervical samples are highly heterogeneous, largely comprised of maternal cervical cells with only a small quantity of trophoblast cells. In order to use these rare cells for diagnostic applications, there is a need to enrich and isolate them from the heterogeneous maternal sample. Our goal was to investigate the use of gravitational flow on an inclined surface and optimize parameters including angle of incline, surface material, incubation time on the surface, solution volume, and device channel width in order to identify a design allowing label-free enrichment of trophoblast cells. In this work we detail the development of a new method and device for controlling cell adhesion to a surface vs. rolling into a collection area. The enrichment device design was developed for ease of use by non-specialized personal and on a slide surface for the ability to be directly integrated onto an automatic cell picker instrument, which can be used for downstream single cell isolation. JEG-3 trophoblast cells were used with clinical cervical samples to present the effect of the different optimization parameters on enrichment. We further provide an assessment of the impact shear stress and thickness of the liquid layer has on cell enrichment. We found that this method provides a maximum JEG-3 enrichment using polystyrene surfaces at a 50° incline with a 5 min incubation period prior to inclined flow. This resulted in a 396 ± 52% increase in purity of the trophoblast cells from the clinical cervical samples as confirmed using human leukocyte antigen G (HLA-G) antibody staining with fluorescence imaging to identify JEG-3 cells. Ultimately, this method is inexpensive, quick, and has the potential for direct integration into fetal cell isolation platforms.


Subject(s)
Cell Separation/methods , Trophoblasts/physiology , Cell Adhesion , Cell Line , Cervix Uteri/cytology , Cervix Uteri/physiology , Female , Humans , Polystyrenes , Pregnancy
14.
Probiotics Antimicrob Proteins ; 13(2): 506-517, 2021 04.
Article in English | MEDLINE | ID: mdl-32980974

ABSTRACT

Streptococcus mutans is considered to be a major bacterium involved in dental caries, and the control of virulence mechanisms is fundamental to prevent disease. Probiotics present a promising preventive method; however, the use of probiotics requires its incorporation into delivery materials to facilitate oral colonization. Thus, we performed a comprehensive study examining preventive effects of Lactobacillus paracasei 28.4-enriched gellan hydrogel materials to inhibit S. mutans in planktonic and biofilm states, addressing its influence in the production of extracellular polysaccharides (EPS) and altered gene expression of several cariogenic virulence factors. L. paracasei 28.4, a strain isolated from the oral cavity of a caries-free individual, was incorporated in three gellan hydrogels (0.5%, 0.75%, and 1% w/v). The pretreatment with probiotic-gellan formulations provided a release of L. paracasei cells over 24 h that was sufficient to inhibit the planktonic growth of S. mutans, independent of the gellan concentrations and pH variations. This pretreatment also had inhibitory activity against S. mutans biofilms, exhibiting a reduction of 0.57 to 1.54 log10 in CFU/mL (p < 0.0001) and a decrease of 68.8 to 71.3% in total biomass (p < 0.0001) compared with the control group. These inhibitory effects were associated with the decreased production of EPS by 80% (p < 0.0001) and the downregulation of luxS, brpA, gbpB, and gtfB genes. The gellan formulation containing L. paracasei 28.4 exhibited probiotic effects for preventing S. mutans growth, biofilm formation, and production of cariogenic factors to suggest possible use in tooth decay prevention.


Subject(s)
Dental Caries , Lacticaseibacillus paracasei , Probiotics , Streptococcus mutans/pathogenicity , Biofilms , Dental Caries/prevention & control , Humans , Lacticaseibacillus paracasei/physiology , Polysaccharides, Bacterial , Virulence Factors
15.
Front Microbiol ; 11: 538602, 2020.
Article in English | MEDLINE | ID: mdl-33042051

ABSTRACT

Candida species can readily colonize a multitude of indwelling devices, leading to biofilm formation. These three-dimensional, surface-associated Candida communities employ a multitude of sophisticated mechanisms to evade treatment, leading to persistent and recurrent infections with high mortality rates. Further complicating matters, the current arsenal of antifungal therapeutics that are effective against biofilms is extremely limited. Antifungal biomaterials are gaining interest as an effective strategy for combating Candida biofilm infections. In this review, we explore biomaterials developed to prevent Candida biofilm formation and those that treat existing biofilms. Surface functionalization of devices employing clinically utilized antifungals, other antifungal molecules, and antifungal polymers has been extremely effective at preventing fungi attachment, which is the first step of biofilm formation. Several mechanisms can lead to this attachment inhibition, including contact killing and release-based killing of surrounding planktonic cells. Eliminating mature biofilms is arguably much more difficult than prevention. Nanoparticles have shown the most promise in disrupting existing biofilms, with the potential to penetrate the dense fungal biofilm matrix and locally target fungal cells. We will describe recent advances in both surface functionalization and nanoparticle therapeutics for the treatment of Candida biofilms.

16.
Chem Commun (Camb) ; 56(75): 11098-11101, 2020 Sep 25.
Article in English | MEDLINE | ID: mdl-32812953

ABSTRACT

We report the conjugation of a chromogenic cephalosporin ß-lactamase (ßL) substrate to polymers and integration into biomaterials for facile, visual ßL detection. Identification of these bacterial enzymes, which are a leading cause of antibiotic resistance, is critical in the treatment of infectious diseases. The ßL substrate polymer conjugate undergoes a clear to deep yellow color change upon incubation with common pathogenic Gram-positive and Gram-negative bacteria species. We have demonstrated the feasibility of formulating hydrogels with the ßL substrate covalently tethered to a poly(ethylene glycol) (PEG) polymer matrix, exhibiting a visible color change in the presence of ßLs. This approach has the potential to be used in diagnostic biomaterials for point-of-care detection of ßL-producing bacteria, helping combat the spread of drug resistant microbes.


Subject(s)
Anti-Bacterial Agents/pharmacology , Biocompatible Materials/pharmacology , Chromogenic Compounds/pharmacology , Gram-Negative Bacteria/drug effects , Gram-Positive Bacteria/drug effects , beta-Lactamases/analysis , Anti-Bacterial Agents/chemical synthesis , Anti-Bacterial Agents/chemistry , Biocompatible Materials/chemical synthesis , Biocompatible Materials/chemistry , Cephalosporins/chemistry , Cephalosporins/pharmacology , Chromogenic Compounds/chemical synthesis , Chromogenic Compounds/chemistry , Drug Resistance, Microbial/drug effects , Gram-Negative Bacteria/metabolism , Gram-Positive Bacteria/metabolism , Humans , Hydrogels/chemistry , Hydrogels/pharmacology , Microbial Sensitivity Tests , Molecular Structure , Polyethylene Glycols/chemistry , Polyethylene Glycols/pharmacology , beta-Lactamases/metabolism
17.
ACS Appl Mater Interfaces ; 12(28): 31099-31111, 2020 Jul 15.
Article in English | MEDLINE | ID: mdl-32558532

ABSTRACT

The placenta plays a key role in regulating the maternal-fetal transport but it is a difficult organ to study due to a lack of existing in vitro models. Lipid bilayers inspired by the placenta can provide a facile new in vitro tool with promise for screening molecular transport across this important organ. Here we developed lipid bilayers that mimic the composition of human placental trophoblast cells at different times during the course of pregnancy. Mass spectrometry identified five major lipid classes (phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, phosphatidylserine, and sphingomyelin) present at varying concentrations in trophoblasts representative of the first and third trimesters and full-term placenta. We successfully developed supported and suspended lipid bilayers mimicking these trophoblast lipid compositions and then demonstrated the utility of these synthetic placenta models for investigating molecular interactions. Specifically, we investigated the interactions with di(2-ethylhexyl) phthalate (DEHP), a common plasticizer and environmental toxicant, and amphotericin B, a common yet toxic, antifungal therapeutic. Overall, we observed that DEHP adsorbs and potentially embeds itself within all placental lipid bilayers, with varying levels of interaction. For both amphotericin B and a liposomal formulation of amphotericin B, AmBisome, we noted lower levels of permeation in transport studies with bilayers and trophoblast cells compared with DEHP, likely driven by differences in size. AmBisome interacted less with both the supported and suspended placental lipid bilayers in comparison to amphotericin B, suggesting that drug delivery carriers can vary the impact of a pharmaceutical agent on these lipid structures. We found that the apparent permeability observed in suspended bilayers was approximately an order of magnitude less than those observed for trophoblast monolayers, which is typical of lipid bilayers. Ultimately, these placenta mimetic lipid bilayers can serve as a platform for the rapid initial screening of molecular interactions with the maternal-fetal interface to better inform future testing.


Subject(s)
Lipid Bilayers/chemistry , Placenta/cytology , Trophoblasts/cytology , Amphotericin B/chemistry , Diethylhexyl Phthalate/chemistry , Female , Humans , Phosphatidylcholines/chemistry , Phosphatidylethanolamines/chemistry , Phosphatidylinositols/chemistry , Phosphatidylserines/chemistry , Plasticizers/chemistry , Pregnancy , Quartz Crystal Microbalance Techniques , Sphingomyelins/chemistry
18.
Chem Commun (Camb) ; 56(55): 7661-7664, 2020 Jul 09.
Article in English | MEDLINE | ID: mdl-32520061

ABSTRACT

We introduce an innovative approach to adhere mesenchymal stem cells (MSCs) to a hydrogel scaffold by nucleating adhesion through strain-promoted click chemistry. This method yields a significant increase in cell viability compared to non-functionalized and RGD peptide functionalized hydrogels, providing a promising alternative to traditional biomaterials cell attachment approaches.


Subject(s)
Biocompatible Materials/chemistry , Cell Adhesion , Click Chemistry , Hydrogels/chemistry , Alkynes/chemistry , Azides/chemistry , Biocompatible Materials/pharmacology , Cell Adhesion/drug effects , Cell Survival/drug effects , Cycloaddition Reaction , Humans , Hydrogels/pharmacology , Mesenchymal Stem Cells/cytology , Mesenchymal Stem Cells/metabolism , Microscopy, Confocal , Oligopeptides/chemistry , Polysaccharides, Bacterial/chemistry
19.
J Biomed Mater Res A ; 108(11): 2263-2276, 2020 11 01.
Article in English | MEDLINE | ID: mdl-32363762

ABSTRACT

Fungal infections can cause significant patient morbidity and mortality. Nanoparticle therapeutics have the potential to improve treatment of these infections. Here we report the development of liposomal nanoparticles incorporating anidulafungin, a potent antifungal, with the goal of increasing its solubility and aiding in localization to fungi. Liposomes were fabricated with three concentrations of anidulafungin yielding monodisperse ~100 nm unilamellar vesicles. All three formulations inhibited planktonic Candida albicans growth at a minimum inhibitory concentration equivalent to free drug. All three formulations also disrupted preformed C. albicans biofilms, reducing fungal burden by as much as 99%, exhibiting superior biofilm disruption compared with free drug. Liposome formulations tested in vivo in C. albicans infected Galleria mellonella wax moth larvae demonstrated increased survival compared to free drug equivalents, leading to a survival of 33 to 67% of larvae over 7 days depending on the liposome utilized compared with only 25% survival of larvae administered free drug. Liposomal formulations along with free anidulafungin did not cause red blood cell lysis. Ultimately, the liposome formulations reported here increased anidulafungin solubility, displayed promising efficacy against planktonic and biofilm C. albicans, and improved the survival of C. albicans-infected G. mellonella compared to free anidulafungin.


Subject(s)
Anidulafungin/pharmacology , Antifungal Agents/pharmacology , Biofilms/drug effects , Candida albicans/drug effects , Anidulafungin/administration & dosage , Animals , Antifungal Agents/administration & dosage , Candida albicans/physiology , Candidiasis/drug therapy , Candidiasis/veterinary , Humans , Liposomes/chemistry , Nanoparticles/chemistry , Plankton/drug effects
20.
Article in English | MEDLINE | ID: mdl-32253208

ABSTRACT

Probiotics might provide an alternative approach for the control of oral candidiasis. However, studies on the antifungal activity of probiotics in the oral cavity are based on the consumption of yogurt or other dietary products, and it is necessary to use appropriate biomaterials and specific strains to obtain probiotic formulations targeted for local oral administration. In this study, we impregnated gellan gum, a natural biopolymer used as a food additive, with a probiotic and investigated its antifungal activity against Candida albicansLactobacillus paracasei 28.4, a strain recently isolated from the oral cavity of a caries-free individual, was incorporated in several concentrations of gellan gum (0.6% to 1% [wt/vol]). All tested concentrations could incorporate L. paracasei cells while maintaining bacterial viability. Probiotic-gellan gum formulations were stable for 7 days when stored at room temperature or 4°C. Long-term storage of bacterium-impregnated gellan gum was achieved when L. paracasei 28.4 was lyophilized. The probiotic-gellan gum formulations provided a release of L. paracasei cells over 24 h that was sufficient to inhibit the growth of C. albicans, with effects dependent on the cell concentrations incorporated into gellan gum. The probiotic-gellan gum formulations also had inhibitory activity against Candida sp. biofilms by reducing the number of Candida sp. cells (P < 0.0001), decreasing the total biomass (P = 0.0003), and impairing hyphae formation (P = 0.0002), compared to the control group which received no treatment. Interestingly, a probiotic formulation of 1% (wt/vol) gellan gum provided an oral colonization of L. paracasei in mice with approximately 6 log CFU/ml after 10 days. This formulation inhibited C. albicans growth (P < 0.0001), prevented the development of candidiasis lesions (P = 0.0013), and suppressed inflammation (P = 0.0006) compared to the mice not treated in the microscopic analysis of the tongue dorsum. These results indicate that gellan gum is a promising biomaterial and can be used as a carrier system to promote oral colonization for probiotics that prevent oral candidiasis.


Subject(s)
Candidiasis, Oral , Lacticaseibacillus paracasei , Probiotics , Animals , Mice , Polysaccharides, Bacterial
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