RESUMO
Sign-tracking (ST) rats show enhanced cue sensitivity before drug experience that predicts greater discrete cue-induced drug seeking compared with goal-tracking or intermediate rats. Cue-evoked dopamine in the nucleus accumbens (NAc) is a neurobiological signature of sign-tracking behaviors. Here, we examine a critical regulator of the dopamine system, endocannabinoids, which bind the cannabinoid receptor-1 (CB1R) in the ventral tegmental area (VTA) to control cue-evoked striatal dopamine levels. We use cell type-specific optogenetics, intra-VTA pharmacology, and fiber photometry to test the hypothesis that VTA CB1R receptor signaling regulates NAc dopamine levels to control sign tracking. We trained male and female rats in a Pavlovian lever autoshaping (PLA) task to determine their tracking groups before testing the effect of VTA â NAc dopamine inhibition. We found that this circuit is critical for mediating the vigor of the ST response. Upstream of this circuit, intra-VTA infusions of rimonabant, a CB1R inverse agonist, during PLA decrease lever and increase food cup approach in sign-trackers. Using fiber photometry to measure fluorescent signals from a dopamine sensor, GRABDA (AAV9-hSyn-DA2m), we tested the effects of intra-VTA rimonabant on NAc dopamine dynamics during autoshaping in female rats. We found that intra-VTA rimonabant decreased sign-tracking behaviors, which was associated with increases in NAc shell, but not core, dopamine levels during reward delivery [unconditioned stimulus (US)]. Our results suggest that CB1R signaling in the VTA influences the balance between the conditioned stimulus-evoked and US-evoked dopamine responses in the NAc shell and biases behavioral responding to cues in sign-tracking rats.SIGNIFICANCE STATEMENT Substance use disorder (SUD) is a chronically relapsing psychological disorder that affects a subset of individuals who engage in drug use. Recent research suggests that there are individual behavioral and neurobiological differences before drug experience that predict SUD and relapse vulnerabilities. Here, we investigate how midbrain endocannabinoids regulate a brain pathway that is exclusively involved in driving cue-motivated behaviors of sign-tracking rats. This work contributes to our mechanistic understanding of individual vulnerabilities to cue-triggered natural reward seeking that have relevance for drug-motivated behaviors.
Assuntos
Núcleo Accumbens , Área Tegmentar Ventral , Feminino , Ratos , Masculino , Animais , Núcleo Accumbens/fisiologia , Área Tegmentar Ventral/fisiologia , Sinais (Psicologia) , Dopamina/metabolismo , Endocanabinoides/farmacologia , Rimonabanto/farmacologia , Agonismo Inverso de Drogas , Recompensa , Poliésteres/metabolismo , Poliésteres/farmacologiaRESUMO
The emerging "super fungus" Candida auris has become an important threat to human health due to its pandrug resistance and high lethality. Therefore, the development of novel antimicrobial strategy is essential. Antimicrobial photodynamic therapy (aPDT) has excellent performance in clinical applications. However, the relevant study on antifungal activity and the mechanism involved against C. auris remains scarce. Herein, a recyclable and biodegradable polylactic acid-hypocrellin A (PLA-HA) nanofibrous membrane is newly developed. In vitro PLA-HA-aPDT could significantly reduce the survival rate of C. auris plankton and its biofilms, and the fungicidal effect of the membrane is still significant after four repeated uses. Simultaneously, PLA-HA exhibits good biocompatibility and low hemolysis. In vivo experiments show that PLA-HA-aPDT can promote C. auris-infected wound healing, reduce inflammatory response, and without obvious toxic side-effects. Further results reveal that PLA-HA-aPDT could increase endogenous reactive oxygen species (ROS) levels, leading to mitochondrial dysfunction, release of cytochrome C, activation of metacaspase, and nuclear fragmentation, thereby triggering apoptosis of C. auris. Compared with HA, PLA-HA shows stronger controllability and reusability, which can greatly improve the utilization efficiency of HA alone. Taken together, the efficacy, safety and antifungal activity make PLA-HA-aPDT a highly promising antifungal candidate for skin or mucous membrane C. auris infection.
Assuntos
Candida , Nanofibras , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Candida auris , Humanos , Testes de Sensibilidade Microbiana , Poliésteres/farmacologiaRESUMO
BACKGROUND: Muscle mass is important for metastatic prostate cancer survival and quality of life (QoL). The backbone of treatment for men with metastatic castration sensitive prostate cancer (mCSPC) is androgen deprivation therapy (ADT) with an androgen signaling inhibitor. ADT is an effective cancer treatment, but it facilitates significant declines in muscle mass and adverse health outcomes important to mCSPC survivors, such as fatigue, and reductions in physical function, independence, insulin sensitivity, and QoL. In non-metastatic CSPC survivors, resistance training (RT) preserves muscle mass and improves these related health outcomes, but the biggest barrier to RT in CSPC survivors of all stages is fatigue. Creatine monohydrate supplementation coupled with RT (Cr + RT) may address this barrier since creatine plays a critical role in energy metabolism. Cr + RT in cancer-free older adults and other clinical populations improves muscle mass and related health outcomes. Evidence also suggests that creatine supplementation can complement cancer treatment. Thus, Cr + RT is a strategy that addresses gaps in survivorship needs of people with mCSPC. The purpose of this parallel, double-blind randomized controlled trial is to test the effects of 52-weeks of Cr + RT compared with placebo (PLA) and RT (PLA + RT) on muscle mass, other related health outcomes, and markers of cancer progression. METHODS: We will carry out this trial with our team's established, effective, home-based, telehealth RT program in 200 mCSPC survivors receiving ADT, and evaluate outcomes at baseline, 24-, and 52-weeks. RT will occur twice weekly with elastic resistance bands, and an established creatine supplementation protocol will be used for supplementation delivery. Our approach addresses a major facilitator to RT in mCSPC survivors, a home-based RT program, while utilizing a supervised model for safety. DISCUSSION: Findings will improve delivery of comprehensive survivorship care by providing a multicomponent, patient-centered lifestyle strategy to preserve muscle mass, improve health outcomes, and complement cancer treatment (NCT06112990).
Assuntos
Neoplasias da Próstata , Treinamento Resistido , Masculino , Humanos , Idoso , Creatina/uso terapêutico , Creatina/farmacologia , Qualidade de Vida , Antagonistas de Androgênios/uso terapêutico , Neoplasias da Próstata/patologia , Androgênios , Força Muscular , Composição Corporal , Processos Neoplásicos , Método Duplo-Cego , Suplementos Nutricionais/efeitos adversos , Músculos/patologia , Poliésteres/farmacologia , Poliésteres/uso terapêutico , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
Formation of adequate vascular network within engineered three-dimensional (3D) tissue substitutes postimplantation remains a major challenge for the success of biomaterials-based tissue regeneration. To better mimic the in vivo angiogenic and vasculogenic processes, nowadays increasing attention is given to the strategy of functionalizing biomaterial scaffolds with multiple bioactive agents. Aimed at engineering electrospun biomimicking fibers with pro-vasculogenic capability, this study was proposed to functionalize electrospun fibers of polycaprolactone/gelatin (PCL/GT) by cell-free fat extract (CEFFE or FE), a newly emerging natural "cocktail" of cytokines and growth factors extracted from human adipose tissue. This was achieved by having the electrospun PCL/GT fiber surface coated with polydopamine (PDA) followed by PDA-mediated immobilization of FE to generate the pro-vasculogenic fibers of FE-PDA@PCL/GT. It was found that the PDA-coated fibrous mat of PCL/GT exhibited a high FE-loading efficiency (â¼90%) and enabled the FE to be released in a highly sustained manner. The engineered FE-PDA@PCL/GT fibers possess improved cytocompatibility, as evidenced by the enhanced cellular proliferation, migration, and RNA and protein expressions (e.g., CD31, vWF, VE-cadherin) in the human umbilical vein endothelial cells (huvECs) used. Most importantly, the FE-PDA@PCL/GT fibrous scaffolds were found to enormously stimulate tube formation in vitro, microvascular development in the in ovo chick chorioallantoic membrane (CAM) assay, and vascularization of 3D construct in a rat subcutaneous embedding model. This study highlights the potential of currently engineered pro-vasculogenic fibers as a versatile platform for engineering vascularized biomaterial constructs for functional tissue regeneration.
Assuntos
Indóis , Polímeros , Engenharia Tecidual , Alicerces Teciduais , Humanos , Ratos , Animais , Engenharia Tecidual/métodos , Materiais Biocompatíveis , Poliésteres/farmacologia , Células Endoteliais da Veia Umbilical HumanaRESUMO
Biodegradable stents are the most promising alternatives for the treatment of cardiovascular disease nowadays, and the strategy of preparing functional coatings on the surface is highly anticipated for addressing adverse effects such as in-stent restenosis and stent thrombosis. Yet, inadequate mechanical stability and biomultifunctionality limit their clinical application. In this study, we developed a multicross-linking hydrogel on the polylactic acid substrates by dip coating that boasts impressive antithrombotic ability, antibacterial capability, mechanical stability, and self-healing ability. Gelatin methacryloyl, carboxymethyl chitosan, and oxidized sodium alginate construct a double-cross-linking hydrogel through the dynamic Schiff base chemical and in situ blue initiation reaction. Inspired by the adhesion mechanism employed by mussels, a triple-cross-linked hydrogel is formed with the addition of tannic acid to increase the adhesion and antibiofouling properties. The strength and hydrophilicity of hydrogel coating are regulated by changing the composition ratio and cross-linking degree. It has been demonstrated in tests in vitro that the hydrogel coating significantly reduces the adhesion of proteins, MC3T3-E1 cells, platelets, and bacteria by 85% and minimizes the formation of blood clots. The hydrogel coating also exhibits excellent antimicrobial in vitro and antiinflammatory properties in vivo, indicating its potential value in vascular intervention and other biomedical fields.
Assuntos
Anti-Inflamatórios , Anticoagulantes , Bivalves , Poliésteres , Stents , Animais , Bivalves/química , Camundongos , Poliésteres/química , Poliésteres/farmacologia , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/química , Stents/efeitos adversos , Anticoagulantes/química , Anticoagulantes/farmacologia , Gelatina/química , Hidrogéis/química , Hidrogéis/farmacologia , Quitosana/química , Quitosana/análogos & derivados , Quitosana/farmacologia , Alginatos/química , Alginatos/farmacologia , Materiais Revestidos Biocompatíveis/química , Materiais Revestidos Biocompatíveis/farmacologia , Antibacterianos/farmacologia , Antibacterianos/química , Taninos/química , Taninos/farmacologia , Humanos , MetacrilatosRESUMO
Membrane-active antimicrobial materials are promising substances to fight antimicrobial resistance. Herein, crystallization-driven self-assembly (CDSA) is employed for the preparation of nanoparticles with different morphologies, and their bioactivity is explored. Block copolymers (BCPs) featuring a crystallizable and antimicrobial block were synthesized using a combination of ring-opening and photoiniferter RAFT polymerizations. Subsequently formed nanostructures formed by CDSA could not be deprotected without degradation of the structures. CDSA of deprotected BCPs yielded 2D diamond-shaped nanoplatelets in MeOH, while spherical nanostructures were observed for assembly in water. Platelets exhibited improved antibacterial capabilities against two Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) compared to their spherical counterparts. The absence of hemolytic activity leads to the excellent selectivity of platelets. A mechanism based on membrane permeabilization was confirmed via dye-leakage assays. This study emphasized the impact of the shape of nanostructures on their interaction with bacterial cells and how a controlled assembly can improve bioactivity.
Assuntos
Antibacterianos , Cristalização , Escherichia coli , Poliésteres , Pseudomonas aeruginosa , Antibacterianos/farmacologia , Antibacterianos/química , Pseudomonas aeruginosa/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Poliésteres/química , Poliésteres/farmacologia , Nanopartículas/química , Nanoestruturas/química , Testes de Sensibilidade Microbiana , Humanos , Polímeros/química , Polímeros/farmacologia , Hemólise/efeitos dos fármacosRESUMO
Drug dependence is a chronic brain disease characterized by craving and recurrent episodes of relapse. Tramadol HCl is a promising agent for withdrawal symptoms management, considering its relatively low abuse potential and safety. Oral administration, however, is not preferred in abstinence maintenance programs. Introducing an implantable, long-lasting formula is suggested to help outpatient abstinence programs achieve higher rates of treatment continuation. Tramadol implants (T350 and T650) were prepared on polycaprolactone polymer ribbons by the wet method. Male Wistar rats were adapted to heroin-conditioned place preference (CPP) at escalating doses (3-30 mg/kg, intraperitoneally, for 14 days). Implants were surgically implanted in the back skin of rats. After 14 days, the CPP score was recorded. Naloxone (1â mg/kg, intraperitoneally) was used to induce withdrawal on day 15, and symptoms were scored. Elevated plus maze and open field tests were performed for anxiety-related symptoms. Striata were analyzed for neurochemical changes reflected in dopamine, 3,4-dihydroxyphenyl acetic acid, gamma-aminobutyric acid, and serotonin levels. Brain oxidative changes including glutathione and lipid peroxides were assessed. The tramadol implants (T350 and T650) reduced heroin CPP and limited naloxone-induced withdrawal symptoms. The striata showed increased levels of 3,4-dihydroxyphenyl acetic acid, and serotonin and decreased levels of gamma-aminobutyric acid and dopamine after heroin withdrawal induction, which were reversed after implanting T350 and T650. Implants restore the brain oxidative state. Nonsignificant low naloxone-induced withdrawal score after the implant was used in naive subjects indicating low abuse potential of the implants. The presented tramadol implants were effective at diminishing heroin CPP and withdrawal in rats, suggesting further investigations for application in the management of opioid withdrawal.
Assuntos
Heroína , Naloxona , Poliésteres , Ratos Wistar , Síndrome de Abstinência a Substâncias , Tramadol , Animais , Tramadol/farmacologia , Síndrome de Abstinência a Substâncias/tratamento farmacológico , Masculino , Heroína/farmacologia , Heroína/administração & dosagem , Ratos , Poliésteres/farmacologia , Naloxona/farmacologia , Implantes de Medicamento , Dependência de Heroína/tratamento farmacológico , Relação Dose-Resposta a Droga , Analgésicos Opioides/farmacologia , Analgésicos Opioides/administração & dosagem , Antagonistas de Entorpecentes/farmacologiaRESUMO
Graphene oxide nanosheet (GO) is a multifunctional platform for binding with nanoparticles and stacking with two dimensional substrates. In this study, GO nanosheets were sonochemically decorated with zinc oxide nanoparticles (ZnO) and self-assembled into a hydrogel of GO-ZnO nanocomposite. The GO-ZnO hydrogel structure is a bioinspired approach for preserving graphene-based nanosheets from van der Waals stacking. X-ray diffraction analysis (XRD) showed that the sonochemical synthesis led to the formation of ZnO crystals on GO platforms. High water content (97.2%) of GO-ZnO hydrogel provided good property of ultrasonic dispersibility in water. Ultraviolet-visible spectroscopic analysis (UV-vis) revealed that optical band gap energy of ZnO nanoparticles (â¼3.2 eV) GO-ZnO nanosheets (â¼2.83 eV). Agar well diffusion tests presented effective antibacterial activities of GO-ZnO hydrogel against gram-negative bacteria (E. coli) and gram-positive bacteria (S. aureus). Especially, GO-ZnO hydrogel was directly used for brush painting on biodegradable polylactide (PLA) thin films. Graphene-based nanosheets with large surface area are key to van der Waals stacking and adhesion of GO-ZnO coating to the PLA substrate. The GO-ZnO/PLA films were characterized using photography, light transmittance spectroscopy, coating stability, scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopic mapping (EDS), antibacterial test and mechanical tensile measurement. Specifically, GO-ZnO coating on PLA substrate exhibited stability in aqueous food simulants for packaging application. GO-ZnO coating inhibited the infectious growth ofE. colibiofilm. GO-ZnO/PLA films had strong tensile strength and elastic modulus. As a result, the investigation of antibacterial GO-ZnO hydrogel and GO-ZnO coating on PLA film is fundamental for sustainable development of packaging and biomedical applications.
Assuntos
Antibacterianos , Escherichia coli , Grafite , Hidrogéis , Poliésteres , Staphylococcus aureus , Óxido de Zinco , Óxido de Zinco/química , Óxido de Zinco/farmacologia , Grafite/química , Grafite/farmacologia , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/síntese química , Poliésteres/química , Poliésteres/farmacologia , Escherichia coli/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Hidrogéis/química , Hidrogéis/farmacologia , Hidrogéis/síntese química , Testes de Sensibilidade Microbiana , Nanocompostos/química , Ondas UltrassônicasRESUMO
Epigenetic change has been found to play an important role in cell differentiation and regulation and the dental pulp stem cell in tissue engineering is gaining attention due to the ability of cells to differentiate into odontoblast and other cells. This study evaluated the influence of poly L- lactic acid with hydroxyapatite-coated with polyaniline scaffold (PLLA/HA/PANI) on dental pulp stem cell (DPSC) proliferation and differentiation. After scaffold preparation and DPSCs seeding, the cells proliferation and differentiation were evaluated by immunocytochemistry assay and cell viability was measured by cytotoxicity / MTT assay. The results showed (PLLA/HA/PANI) scaffold facilitates DPSC proliferation and differentiation with gene expression. This finding underscores the promise of this biomaterial combination as a scaffold for dental tissue regeneration and application.
Assuntos
Materiais Biocompatíveis , Diferenciação Celular , Proliferação de Células , Polpa Dentária , Durapatita , Odontoblastos , Osteoblastos , Células-Tronco , Alicerces Teciduais , Polpa Dentária/citologia , Humanos , Diferenciação Celular/efeitos dos fármacos , Odontoblastos/citologia , Odontoblastos/efeitos dos fármacos , Odontoblastos/metabolismo , Alicerces Teciduais/química , Células-Tronco/citologia , Células-Tronco/metabolismo , Células-Tronco/efeitos dos fármacos , Osteoblastos/citologia , Osteoblastos/efeitos dos fármacos , Osteoblastos/metabolismo , Proliferação de Células/efeitos dos fármacos , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Durapatita/química , Durapatita/farmacologia , Compostos de Anilina/farmacologia , Compostos de Anilina/química , Poliésteres/química , Poliésteres/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Engenharia Tecidual/métodosRESUMO
BACKGROUND: The integration of stem cells, signaling molecules, and biomaterial scaffolds is fundamental for the successful engineering of functional bone tissue. Currently, the development of composite scaffolds has emerged as an attractive approach to meet the criteria of ideal scaffolds utilized in bone tissue engineering (BTE) for facilitating bone regeneration in bone defects. Recently, the incorporation of polycaprolactone (PCL) with hydroxyapatite (HA) has been developed as one of the suitable substitutes for BTE applications owing to their promising osteogenic properties. In this study, a three-dimensional (3D) scaffold composed of PCL integrated with HA (PCL/HA) was prepared and assessed for its ability to support osteogenesis in vitro. Furthermore, this scaffold was evaluated explicitly for its efficacy in promoting the proliferation and osteogenic differentiation of canine bone marrow-derived mesenchymal stem cells (cBM-MSCs) to fill the knowledge gap regarding the use of composite scaffolds for BTE in the veterinary orthopedics field. RESULTS: Our findings indicate that the PCL/HA scaffolds substantially supported the proliferation of cBM-MSCs. Notably, the group subjected to osteogenic induction exhibited a markedly upregulated expression of the osteogenic gene osterix (OSX) compared to the control group. Additionally, the construction of 3D scaffold constructs with differentiated cells and an extracellular matrix (ECM) was successfully imaged using scanning electron microscopy. Elemental analysis using a scanning electron microscope coupled with energy-dispersive X-ray spectroscopy confirmed that these constructs possessed the mineral content of bone-like compositions, particularly the presence of calcium and phosphorus. CONCLUSIONS: This research highlights the synergistic potential of PCL/HA scaffolds in concert with cBM-MSCs, presenting a multidisciplinary approach to scaffold fabrication that effectively regulates cell proliferation and osteogenic differentiation. Future in vivo studies focusing on the repair and regeneration of bone defects are warranted to further explore the regenerative capacity of these constructs, with the ultimate goal of assessing their potential in veterinary clinical applications.
Assuntos
Regeneração Óssea , Durapatita , Células-Tronco Mesenquimais , Osteogênese , Poliésteres , Alicerces Teciduais , Animais , Cães , Poliésteres/química , Poliésteres/farmacologia , Alicerces Teciduais/química , Osteogênese/efeitos dos fármacos , Durapatita/química , Durapatita/farmacologia , Células-Tronco Mesenquimais/fisiologia , Regeneração Óssea/efeitos dos fármacos , Proliferação de Células , Diferenciação Celular/efeitos dos fármacos , Engenharia Tecidual/métodosRESUMO
Poly L-lactic acid (PLLA) fillers stimulate collagen synthesis by activating various immune cells and fibroblasts. Piezo1, an ion channel, responds to mechanical stimuli, including changes in extracellular matrix stiffness, by mediating Ca2+ influx. Given that elevated intracellular Ca2+ levels trigger signaling pathways associated with fibroblast proliferation, Piezo1 is a pivotal regulator of collagen synthesis and tissue fibrosis. The aim of the present study was to investigate the impact of PLLA on dermal collagen synthesis by activating Piezo1 in both an H2O2-induced cellular senescence model in vitro and aged animal skin in vivo. PLLA elevated intracellular Ca2+ levels in senescent fibroblasts, which was attenuated by the Piezo1 inhibitor GsMTx4. Furthermore, PLLA treatment increased the expression of phosphorylated ERK1/2 to total ERK1/2 (pERK1/2/ERK1/2) and phosphorylated AKT to total AKT (pAKT/AKT), indicating enhanced pathway activation. This was accompanied by upregulation of cell cycle-regulating proteins (CDK4 and cyclin D1), promoting the proliferation of senescent fibroblasts. Additionally, PLLA promoted the expression of phosphorylated mTOR/S6K1/4EBP1, TGF-ß, and Collagen I/III in senescent fibroblasts, with GsMTx4 treatment mitigating these effects. In aged skin, PLLA treatment similarly upregulated the expression of pERK1/2/ERK1/2, pAKT/AKT, CDK4, cyclin D1, mTOR/S6K1/4EBP1, TGF-ß, and Collagen I/III. In summary, our findings suggest Piezo1's involvement in PLLA-induced collagen synthesis, mediated by heightened activation of cell proliferation signaling pathways such as pERK1/2/ERK1/2, pAKT/AKT, and phosphorylated mTOR/S6K1/4EBP1, underscoring the therapeutic potential of PLLA in tissue regeneration.
Assuntos
Colágeno , Fibroblastos , Poliésteres , Animais , Poliésteres/farmacologia , Poliésteres/química , Fibroblastos/metabolismo , Fibroblastos/efeitos dos fármacos , Colágeno/metabolismo , Colágeno/biossíntese , Canais Iônicos/metabolismo , Camundongos , Pele/metabolismo , Pele/efeitos dos fármacos , Envelhecimento da Pele/efeitos dos fármacos , Senescência Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Cálcio/metabolismo , Transdução de Sinais/efeitos dos fármacos , HumanosRESUMO
Polyester dendrimers based on 2,2 bis(hydroxymethyl)propionic acid have been reported to be degradable, non-toxic, and exhibit good antimicrobial activity when decorated with cationic charges. However, these systems exhibit rapid depolymerization, from the outer layer inwards in physiological neutral pHs, which potentially restricts their use in biomedical applications. In this study, we present a new generation of amine functional bis-MPA polyester dendrimers with increased hydrolytic stability as well as antibacterial activity for Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli) and Pseudomonas aeruginosa (P. aeruginosa) planktonic bacteria strains. These new derivatives show generally good cytocompatibility for the concentrations they are active toward bacteria, in monocyte/macrophage-like cells (Raw 264.7), and human dermal fibroblasts. Fluoride - promoted esterification chemistry, anhydride chemistry, and click reactions were utilized to produce a library from generations 1-3 and with cationic peripheral groups ranging from 6 to 24 groups, respectively. The dendrimers were successfully purified using conventional purification techniques as well as characterized by matrix-assisted laser desorption ionization time-of-flight mass spectroscopy, nuclear magnetic resonance, and size exclusion chromatography. As proof of synthetic versatility, dendritic-linear-dendritic block copolymer were successfully synthesized to display cysteamine peripheral functionalities as well as the scaffolding ability with biomedically relevant lipoic acid and methoxy polyethylene glycol.
Assuntos
Dendrímeros , Poliésteres , Humanos , Poliésteres/farmacologia , Poliésteres/química , Dendrímeros/química , Staphylococcus aureus , Escherichia coli , Antibacterianos/farmacologiaRESUMO
In this study, gold nanoparticles were loaded into poly (ε-caprolactone) (PCL)/gelatin nanofibrous matrices to fabricate a potential wound dressing. The mats were produced by electrospinning of PCL/gelatin solution supplemented with synthesized gold nanoparticles (200, 400 and 800 ppm). Prepared scaffolds were investigated regarding their chemical properties, morphology, mechanical properties, surface wettability, water-uptake capacity, water vapor permeability, porosity, blood compatibility, microbial penetration test and cellular response. In addition to in vivo study, a full-thickness excisional wound in a rat model was used to evaluate the healing effect of prepared scaffolds. Results showed appropriate mechanical properties and porosity of prepared scaffolds. With L929 cells, the PCL/gelatin scaffold containing 400 ppm gold nanoparticles demonstrated the greatest cell growth. In vivo results validated the favorable wound-healing benefits of the scaffold incorporating gold nanoparticles, which triggered wound healing compared to sterile gauze. Our results showed the capability of nanofibrous matrices containing gold nanoparticles for successful wound treatment.
Assuntos
Nanopartículas Metálicas , Nanofibras , Ratos , Animais , Cicatrização , Gelatina/farmacologia , Ouro/farmacologia , Nanofibras/química , Poliésteres/farmacologia , Poliésteres/química , Alicerces Teciduais/químicaRESUMO
With increased diabetes incidence, diabetic wound healing is one of the most common diabetes complications and is characterized by easy infection, chronic inflammation, and reduced vascularization. To address these issues, biomaterials with multifunctional antibacterial, immunomodulatory, and angiogenic properties must be developed to improve overall diabetic wound healing for patients. In our study, we prepared porous poly (L-lactic acid) (PLA) nanofiber membranes using electrospinning and solvent evaporation methods. Then, sulfated chitosan (SCS) combined with polydopamine-gentamicin (PDA-GS) was stepwise modified onto porous PLA nanofiber membrane surfaces. Controlled GS release was facilitated via dopamine self-polymerization to prevent early stage infection. PDA was also applied to PLA nanofiber membranes to suppress inflammation. In vitro cell tests results showed that PLA/SCS/PDA-GS nanofiber membranes immuomodulated macrophage toward the M2 phenotype and increased endogenous vascular endothelial growth factor secretion to induce vascularization. Moreover, SCS-contained PLA nanofiber membranes also showed good potential in enhancing macrophage trans-differentiation to fibroblasts, thereby improving wound healing processes. Furthermore, our in vitro antibacterial studies against Staphylococcus aureus indicated the effective antibacterial properties of the PLA/SCS/PDA-GS nanofiber membranes. In summary, our novel porous PLA/SCS/PDA-GS nanofiber membranes possessing enhanced antibacterial, anti-inflammatory, and angiogenic properties demonstrate promising potential in diabetic wound healing processes.
Assuntos
Quitosana , Diabetes Mellitus , Nanofibras , Humanos , Porosidade , Fator A de Crescimento do Endotélio Vascular , Poliésteres/farmacologia , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Cicatrização , Anti-Inflamatórios , Ácido LácticoRESUMO
BACKGROUND This study evaluated the clinical efficacy of polylactic acid (PLA) membranes in guiding bone regeneration in anterior maxillary implants. MATERIAL AND METHODS Forty-eight participants with maxillary anterior tooth loss requiring implantation with guided bone regeneration were recruited and randomly divided into 2 groups (n=24): the PLA membrane (experimental) and the Bio-Gide membrane (control) group. Wound healing was observed at 1 week and 1 month postoperatively. Cone beam CT was performed immediately and at 6 and 36 months postoperatively. Soft-tissue parameters were measured at 18 and 36 months postoperatively. Implant stability quotient (ISQ) and patient satisfaction were separately evaluated at 6 and 18 months after the operation. The independent sample t test and chi-square test were preformed to analyze quantitative and descriptive statistics, respectively. RESULTS No implants were lost and there were no statistically significant differences in ISQ between the 2 groups. The labial bone plates in the experimental group exhibited a non-significantly greater extent of absorption than did the control group at 6 and 18 months postoperatively. Soft-tissue parameters did not reveal inferior results for the experimental group. Patients in both groups were satisfied. CONCLUSIONS PLA membranes are comparable to Bio-Gide in terms of the effectiveness and safety and can be used as a barrier membrane to guide bone regeneration in clinical practice.
Assuntos
Regeneração Óssea , Implantes Dentários , Humanos , Poliésteres/farmacologia , Resultado do Tratamento , CicatrizaçãoRESUMO
Salmonella is a food-borne microorganism that is also a zoonotic bacterial hazard in the food sector. This study determined how well a mixed culture of Salmonella Kentucky formed biofilms on plastic (PLA), silicon rubber (SR), rubber gloves (RG), chicken skin and eggshell surfaces. In vitro interactions between the histone deacetylase inhibitor-vorinostat (SAHA)-and S. enterica serotype Kentucky were examined utilizing biofilms. The minimum inhibitory concentration (MIC) of SAHA was 120 µg mL-1. The addition of sub-MIC (60 µg mL-1) of SAHA decreased biofilm formation for 24 h on PLA, SR, RG, Chicken skin, and eggshell by 3.98, 3.84, 4.11, 2.86 and 3.01 log (p < 0.05), respectively. In addition, the initial rate of bacterial biofilm formation was higher on chicken skin than on other surfaces, but the inhibitory effect was reduced. Consistent with this conclusion, virulence genes expression (avrA, rpoS and hilA) and quorum-sensing (QS) gene (luxS) was considerably downregulated at sub-MIC of SAHA. SAHA has potential as an anti-biofilm agent against S. enterica serotype Kentucky biofilm, mostly by inhibiting virulence and quorum-sensing gene expression, proving the histone deacetylase inhibitor could be used to control food-borne biofilms in the food industry.
Assuntos
Biofilmes , Salmonella enterica , Salmonella enterica/genética , Vorinostat/farmacologia , Virulência , Sorogrupo , Inibidores de Histona Desacetilases/farmacologia , Kentucky , Borracha , Percepção de Quorum , Poliésteres/farmacologiaRESUMO
Chagas disease (CD) remains neglected and causes high morbidity and mortality. The great difficulty is the lack of effective treatment. The current drugs cause side effects and have limited therapeutic efficacy in the chronic phase. This study aims to fulfil some gaps in studies of the natural substance lychnopholide nanoencapsulated LYC-PLA-PEG-NC (LYC-NC) and free (Free-LYC): the activity in epimastigotes and amastigotes to determine its selectivity index (SI), the therapeutic efficacy in mice infected with Colombian Trypanosoma cruzi strain and insight of the mechanism of LYC-NC action on T. cruzi. The SI was obtained by calculation of the ratio between the IC50 value toward H9c2 cells divided by the IC50 value in the anti-T. cruzi test. Infected Swiss mice were treated with 2 and 12 mg/kg/day via intravenous and oral, respectively, and the therapeutic efficacy was determined. The IC50 of LYC-NC and Free-LYC for epimastigotes of T. cruzi were similar. Both were active against amastigotes in cell culture, particularly Free-LYC. The SI of LYC-NC and Free-LYC were 45.38 and 32.11, respectively. LYC-NC 2 and 12 mg/kg/day cured parasitologically, 62.5% and 80% of the animals, respectively, infected with a strain resistant to treatment. The fluorescent NC was distributed in the cardiomyocyte cytoplasm, infected or not, and interacted with the trypomastigotes. Together, these results represent advances in demonstrating LYC as a potent new therapeutic option for treating CD.
Assuntos
Doença de Chagas , Nanocápsulas , Nitroimidazóis , Tripanossomicidas , Trypanosoma cruzi , Animais , Camundongos , Nifurtimox/uso terapêutico , Nitroimidazóis/farmacologia , Nitroimidazóis/uso terapêutico , Doença de Chagas/tratamento farmacológico , Poliésteres/farmacologia , Poliésteres/uso terapêutico , Tripanossomicidas/farmacologia , Tripanossomicidas/uso terapêuticoRESUMO
PURPOSE: To determine whether carbohydrate mouth rinsing would improve endurance running performance of tropical natives in a warm-humid (30 °C and 70% relative humidity) environment. METHOD: Twelve endurance male runners [age 25 ± 3 years; peak aerobic capacity ([Formula: see text]O2peak) 57.6 ± 3.6 mL.kg-1.min-1] completed three time-to-exhaustion (TTE) trials at ~ 70% [Formula: see text]O2peak while swilling 25 ml of a 6% carbohydrate (CHO) or taste-matched placebo (PLA) as well as no mouth rinse performed in the control (CON) trial. RESULTS: TTE performance was significantly longer in both CHO and PLA trials when compared with the CON trial (54.7 ± 5.4 and 53.6 ± 5.1 vs. 48.4 ± 3.6 min, respectively; p < 0.001 and p = 0.012, respectively), but was not significantly different between CHO and PLA trials (p = 1.000). The rating of perceived exertion was not different between the CHO and PLA trials, however, was significantly affected when compared to the CON trial (p < 0.001). A similar effect was observed for perceived arousal level between the CHO and PLA trials to the CON trial. Core temperature, mean skin temperature and skin blood flow were not significantly different between the three trials (all p > 0.05). Similarly, plasma lactate and glucose as well as exercise heart rate were not influenced by the trials. CONCLUSIONS: The present study demonstrates that mouth rinsing, whether carbohydrate or placebo, provides an ergogenic benefit to running endurance when compared to CON in a heat stress environment. Nevertheless, the results do not support the notion that rinsing a carbohydrate solution provides a greater advantage as previously described among non-heat acclimated individuals within a temperate condition.
Assuntos
Antissépticos Bucais , Corrida , Humanos , Masculino , Adulto Jovem , Adulto , Antissépticos Bucais/farmacologia , Carboidratos da Dieta/farmacologia , Corrida/fisiologia , Exercício Físico/fisiologia , Poliésteres/farmacologia , Resistência Física/fisiologiaRESUMO
PURPOSE: Angiotensin-converting enzyme (ACE) inhibitor treatment is widely applied, but the fact that plasma ACE activity is a potential determinant of training-induced local muscular adaptability is often neglected. Thus, we investigated the hypothesis that ACE inhibition modulates the response to systematic aerobic exercise training on leg and arm muscular adaptations. METHODS: Healthy, untrained, middle-aged participants (40 ± 7 yrs) completed a randomized, double-blinded, placebo-controlled trial. Participants were randomized to placebo (PLA: CaCO3) or ACE inhibitor (ACEi: enalapril) for 8 weeks and completed a supervised, high-intensity exercise training program. Muscular characteristics in the leg and arm were extensively evaluated pre and post-intervention. RESULTS: Forty-eight participants (nACEi = 23, nPLA = 25) completed the trial. Exercise training compliance was above 99%. After training, citrate synthase, 3-hydroxyacyl-CoA dehydrogenase and phosphofructokinase maximal activity were increased in m. vastus lateralis in both groups (all P < 0.05) without statistical differences between them (all time × treatment P > 0.05). In m. deltoideus, citrate synthase maximal activity was upregulated to a greater extent (time × treatment P < 0.05) in PLA (51 [33;69] %) than in ACEi (28 [13;43] %), but the change in 3-hydroxyacyl-CoA dehydrogenase and phosphofructokinase maximal activity was similar between groups. Finally, the training-induced changes in the platelet endothelial cell adhesion molecule-1 protein abundance, a marker of capillary density, were similar in both groups in m. vastus lateralis and m. deltoideus. CONCLUSION: Eight weeks of high-intensity whole-body exercise training improves markers of skeletal muscle mitochondrial oxidative capacity, glycolytic capacity and angiogenesis, with no overall effect of pharmacological ACE inhibition in healthy adults.
Assuntos
Braço , Perna (Membro) , Adulto , Pessoa de Meia-Idade , Humanos , Citrato (si)-Sintase/metabolismo , Braço/fisiologia , Perna (Membro)/fisiologia , Músculo Esquelético/fisiologia , Consumo de Oxigênio/fisiologia , 3-Hidroxiacil-CoA Desidrogenase/metabolismo , Fosfofrutoquinases/metabolismo , Poliésteres/farmacologiaRESUMO
This study compared the appetite and energy intake effects of three post-exercise beverages at a subsequent post-exercise meal. On three occasions, ten active males: (mean ± sd) age 21.3 ± 1.2 y, VË O2peak 58 ± 5 mL/kg/min) performed 30-min cycling at â¼60% VË O2peak and five 4-min intervals at 85% VË O2peak. Post-exercise, placebo (PLA: 57 kJ), skimmed milk (MILK: 1002 kJ) or sucrose (CHO: 1000 kJ) beverages (615 mL) were consumed. Sixty min post-beverage, subjects consumed an ad-libitum pasta lunch in a 30 min eating period. Subjective appetite and plasma acylated ghrelin and plasma glucose were determined pre-exercise, post-exercise and pre-meal, with sensory characteristics of beverages rated. Ad-libitum energy intake in MILK (6746 ± 2035) kJ) was lower than CHO (7762 ± 1921) kJ) (P = 0.038; dz = 0.98; large effect) and tended to be lower than PLA (7672 (2005) kJ) (P = 0.078; dz = 0.76; medium effect). Including energy consumed in beverages, energy intake was greater in CHO than PLA (P = 0.010; dz = 1.24; large effect) or MILK (P = 0.026; dz = 0.98; large effect), with PLA and MILK not different (P = 0.960; dz = 0.02; trial effect). Plasma ghrelin, plasma glucose and appetite were not different between trials. MILK was perceived thicker than CHO (P = 0.020; dz = 1.11; large effect) and creamier than PLA (P = 0.026; dz = 1.06; large effect). These results suggest that when energy balance is important for an exerciser, post-exercise skimmed milk ingestion reduces energy intake compared to a sucrose beverage and might therefore help facilitate recovery/adaptation without affecting energy balance.