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1.
J Biomed Sci ; 31(1): 50, 2024 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-38741159

RESUMEN

BACKGROUND: G-quadruplex DNA (G4) is a non-canonical structure forming in guanine-rich regions, which play a vital role in cancer biology and are now being acknowledged in both nuclear and mitochondrial (mt) genome. However, the impact of G4-based targeted therapy on both nuclear and mt genome, affecting mt function and its underlying mechanisms remain largely unexplored. METHODS: The mechanisms of action and therapeutic effects of a G4-binding platinum(II) complex, Pt-ttpy, on mitochondria were conducted through a comprehensive approaches with in vitro and in vivo models, including ICP-MS for platinum measurement, PCR-based genetic analysis, western blotting (WB), confocal microscope for mt morphology study, extracellular flux analyzer, JC1 and Annexin V apoptosis assay, flow cytometry and high content microscope screening with single-cell quantification of both ROS and mt specific ROS, as well as click-chemistry for IF study of mt translation. Decipher Pt-ttpy effects on nuclear-encoded mt related genes expression were undertaken via RNA-seq, Chip-seq and CUT-RUN assays. RESULTS: Pt-ttpy, shows a highest accumulation in the mitochondria of A2780 cancer cells as compared with two other platinum(II) complexes with no/weak G4-binding properties, Pt-tpy and cisplatin. Pt-ttpy induces mtDNA deletion, copy reduction and transcription inhibition, hindering mt protein translation. Functional analysis reveals potent mt dysfunction without reactive oxygen species (ROS) induction. Mechanistic study provided first evidence that most of mt ribosome genes are highly enriched in G4 structures in their promoter regions, notably, Pt-ttpy impairs most nuclear-encoded mt ribosome genes' transcription through dampening the recruiting of transcription initiation and elongation factors of NELFB and TAF1 to their promoter with G4-enriched sequences. In vivo studies show Pt-ttpy's efficient anti-tumor effects, disrupting mt genome function with fewer side effects than cisplatin. CONCLUSION: This study underscores Pt-ttpy as a G4-binding platinum(II) complex, effectively targeting cancer mitochondria through dual action on mt and nuclear G4-enriched genomes without inducing ROS, offering promise for safer and effective platinum-based G4-targeted cancer therapy.


Asunto(s)
G-Cuádruplex , Mitocondrias , G-Cuádruplex/efectos de los fármacos , Humanos , Mitocondrias/metabolismo , Mitocondrias/efectos de los fármacos , Línea Celular Tumoral , Genoma Mitocondrial , Antineoplásicos/farmacología , Neoplasias/tratamiento farmacológico , Neoplasias/genética , Neoplasias/metabolismo , Platino (Metal)/farmacología , Animales
2.
Annu Rev Biomed Eng ; 20: 353-374, 2018 06 04.
Artículo en Inglés | MEDLINE | ID: mdl-29621404

RESUMEN

Inorganic nanomaterials have witnessed significant advances in areas of medicine including cancer therapy, imaging, and drug delivery, but their use in soft tissue repair and regeneration is in its infancy. Metallic, ceramic, and carbon allotrope nanoparticles have shown promise in facilitating tissue repair and regeneration. Inorganic nanomaterials have been employed to improve stem cell engraftment in cellular therapy, material mechanical stability in tissue repair, electrical conductivity in nerve and cardiac regeneration, adhesion strength in tissue approximation, and antibacterial capacity in wound dressings. These nanomaterials have also been used to improve or replace common surgical materials and restore functionality to damaged tissue. We provide a comprehensive overview of inorganic nanomaterials in tissue repair and regeneration, and discuss their promise and limitations for eventual translation to the clinic.


Asunto(s)
Nanopartículas/química , Nanoestructuras/química , Medicina Regenerativa/instrumentación , Ingeniería de Tejidos/métodos , Animales , Antibacterianos/química , Vendajes , Carbono/química , Sistemas de Liberación de Medicamentos , Conductividad Eléctrica , Humanos , Compuestos Inorgánicos , Nanopartículas del Metal , Regeneración , Regeneración de la Medula Espinal , Cicatrización de Heridas
3.
Arch Biochem Biophys ; 662: 134-142, 2019 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-30529570

RESUMEN

Two novel medicinally important legume lectins from Bauhinia purpurea (BPL) and Wisteria floribunda (WFL) possessing extended sugar binding site were investigated for functional and conformational transitions using biochemical and biophysical techniques as well as bioinformatical tools. Homology model of BPL was constructed using the Schrodinger suite and docked with N-acetyl galactosamine and T-antigen disaccharide (Galß1-3GalNAcαO-Me). The longer loop D in the structure of WFL compared to that in BPL was found to be responsible for its specificity to LacdiNac (ß-D-GalNAc-[1 → 4]-DGlcNAc) over Galß1-3GalNAc. BPL remained functionally stable up to 40 °C whereas WFL remained stable upto 70 °C indicating the strength of the sugar binding site geometry. Both the lectins showed intense but non-specific secondary structure in the range of 65-90 °C. WFL showed rapid aggregation above 80 °C as indicated by light scattering intensity. The lectins showed simultaneous dissociation and multistate unfolding in the vicinity of GdnHCl. At pH 1.0, both the lectins exhibited molten globule like structures, which were characterized further and were found to respond in a different way towards denaturants. The results have provided valuable insights into the molecular basis of the activity and stability of the two lectins.


Asunto(s)
Fabaceae/química , Lectinas/química , Azúcares/química , Wisteria/química , Sitios de Unión , Ligandos , Simulación de Dinámica Molecular , Conformación Proteica
4.
Soft Matter ; 15(39): 7787-7794, 2019 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-31515547

RESUMEN

A generalized method for sorting nanoparticles based on their cores does not exist; it is an immediate necessity, and an approach incorporating cost-effectiveness and biocompatibility is in demand. Therefore, an efficient method for the separation of various mixed core-compositions or dissimilar metallic nanoparticles to their pure forms at the nano-bio interface was developed. Various simple core-combinations of monodispersed nanoparticles with dual cores, including silver plus gold, iron oxide plus gold and platinum plus gold, to the complex three-set core-combinations of platinum plus gold plus silver and platinum plus iron plus gold were sorted using step-gradient centrifugation in a sucrose suspension. Viscosity mediated differential terminal velocities of the nanoparticles permitted diversified dragging at different gradients allowing separation. Stability, purity and properties of the nanoparticles during separation were evaluated based on visual confirmation and by employing advanced instrumentations. Moreover, theoretical studies validated our experimental observations, revealing the roles of various parameters, such as the viscosity of sucrose, the density of the particles and the velocity and duration of centrifugation, involved during the separation process. This remarkably rapid, cost-efficient and sustainable strategy can be adapted to separate other cores of nanoparticles for various biomedical research purposes, primarily to understand nanoparticle induced toxicity and particle fate and transformations in natural biotic environments.

5.
Molecules ; 24(3)2019 01 23.
Artículo en Inglés | MEDLINE | ID: mdl-30678027

RESUMEN

Guanine-rich DNA can form four-stranded structures called G-quadruplexes (G4s) that can regulate many biological processes. Metal complexes have shown high affinity and selectivity toward the quadruplex structure. Here, we report the comparison of a panel of platinum (II) complexes for quadruplex DNA selective recognition by exploring the aromatic core around terpyridine derivatives. Their affinity and selectivity towards G4 structures of various topologies have been evaluated by FRET-melting (Fluorescence Resonance Energy Transfert-melting) and Fluorescent Intercalator Displacement (FID) assays, the latter performed by using three different fluorescent probes (Thiazole Orange (TO), TO-PRO-3, and PhenDV). Their ability to bind covalently to the c-myc G4 structure in vitro and their cytotoxicity potential in two ovarian cancerous cell lines were established. Our results show that the aromatic surface of the metallic ligands governs, in vitro, their affinity, their selectivity for the G4 over the duplex structures, and platination efficiency. However, the structural modifications do not allow significant discrimination among the different G4 topologies. Moreover, all compounds were tested on ovarian cancer cell lines and normal cell lines and were all able to overcome cisplatin resistance highlighting their interest as new anticancer drugs.


Asunto(s)
G-Cuádruplex/efectos de los fármacos , Neoplasias Ováricas/tratamiento farmacológico , Platino (Metal)/química , Proteínas Proto-Oncogénicas c-myc/química , Anticarcinógenos/química , Anticarcinógenos/uso terapéutico , Cisplatino/efectos adversos , Cisplatino/química , Resistencia a Antineoplásicos/efectos de los fármacos , Femenino , Transferencia Resonante de Energía de Fluorescencia , Colorantes Fluorescentes/química , Humanos , Ligandos , Conformación de Ácido Nucleico/efectos de los fármacos , Piridinas/química
6.
Adv Funct Mater ; 28(42)2018 Oct 17.
Artículo en Inglés | MEDLINE | ID: mdl-37138942

RESUMEN

Tissue approximation and repair have been conventionally performed with sutures and staples, but these means are inherently traumatic. Tissue approximation using laser-responsive nanomaterials can lead to rapid tissue sealing and repair, and is an attractive alternative to existing clinical methods. Here, we demonstrate the use of laser-activated nanosealants (LANS) with gold nanorods (GNRs) embedded in silk fibroin polypeptide matrices. The adaptability of LANS for sealing soft tissues is demonstrated using two different modalities: insoluble thin films for internal, intestinal tissue repair, and semi-soluble pastes for external repair, shown by skin repair in live mice. Laser repaired intestinal tissue held over seven times more fluid pressure than sutured intestine and also prevented bacterial leakage. Skin incisions in mice closed using LANS' showed indication of increased mechanical strength and faster repair compared to suturing. Laser-activated silk-GNR nanosealants rapidly seal soft-tissue tears and show high promise for tissue approximation and repair in trauma and routine surgery.

7.
Curr Microbiol ; 74(11): 1332-1336, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28779357

RESUMEN

The twin-arginine translocase (Tat) pathway is involved in the transport of folded proteins in bacteria, and has been implicated in virulence and pathogenesis. A simple but efficient assay based on the quantification of the exopolysaccharide colanic acid was developed as a new means to study Tat function. Colanic acid contains a methylpentose (L-fucose) component, and its production is directly linked to the Tat pathway through the transport of enzymes involved in polysaccharide biosynthesis. Monitoring of L-fucose levels can be applied for identification of new Tat substrates and high-throughput screening of Tat inhibitors for therapeutic applications.


Asunto(s)
Bacterias/enzimología , Pruebas de Enzimas , Ensayos Analíticos de Alto Rendimiento , Proteínas de Transporte de Membrana/metabolismo , Sistema de Translocación de Arginina Gemela/metabolismo , Glucanos/biosíntesis , Polisacáridos/biosíntesis , Transporte de Proteínas
8.
Forensic Sci Int Genet ; 72: 103093, 2024 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-39013214

RESUMEN

Short Tandem Repeat (STR) markers have been the gold standard for human identification testing in the forensic field for the last few decades. The GlobalFiler™ IQC PCR amplification Kit has shown sensitivity, high power of discrimination and is therefore widely used. Samples with limited DNA quantities remain a significant hurdle for streamlined human forensic identification. Reaction volume reduction in a closed system paired with automation can provide solutions to secure DNA profiles when routine methods fall short. We automated and optimized the GlobalFilerTM IQC PCR Amplification Kit on the Magelia®, a closed molecular biology platform, to test whether reaction volume reduction in a confined automated system would improve signal and sensitivity. We evaluated the platform's performance using reference and real casework samples (blood, cigarette butt, saliva and touch DNA) in the context of a 5-fold volume reduction when compared to the routine protocol. This strategy showed distinct advantages over standard treatment, notably increased signal for lower DNA inputs. Importantly, negative casework samples through routine treatment yielded "usable" DNA profiles after amplification using this strategy. This novel approach represents a first proof of concept for a method enabling users to treat limited samples, or to partition routine samples for multiple analyses.

9.
Biomaterials ; 306: 122496, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38373363

RESUMEN

Slow-healing and chronic wounds represent a major global economic and medical burden, and there is significant unmet need for novel therapies which act to both accelerate wound closure and enhance biomechanical recovery of the skin. Here, we report a new approach in which bioactives that augment early stages of wound healing can kickstart and engender effective wound closure in healthy and diabetic, obese animals, and set the stage for subsequent tissue repair processes. We demonstrate that a nanomaterial dressing made of silk fibroin and gold nanorods (GNR) stimulates a pro-neutrophilic, innate immune, and controlled inflammatory wound transcriptomic response. Further, Silk-GNR, lasered into the wound bed, in combination with exogeneous histamine, accelerates early-stage processes in tissue repair leading to effective wound closure. Silk-GNR and histamine enhanced biomechanical recovery of skin, increased transient neoangiogenesis, myofibroblast activation, epithelial-to-mesenchymal transition (EMT) of keratinocytes and a pro-resolving neutrophilic immune response, which are hitherto unknown activities for these bioactives. Predictive and temporally coordinated delivery of growth factor nanoparticles that modulate later stages of tissue repair further accelerated wound closure in healthy and diabetic, obese animals. Our approach of kickstarting healing by delivering the "right bioactive at the right time" stimulates a multifactorial, pro-reparative response by augmenting endogenous healing and immunoregulatory mechanisms and highlights new targets to promote tissue repair.


Asunto(s)
Diabetes Mellitus , Nanoestructuras , Animales , Cicatrización de Heridas , Histamina , Seda , Obesidad
10.
Biomaterials ; 311: 122668, 2024 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-38908232

RESUMEN

Conventional wound approximation devices, including sutures, staples, and glues, are widely used but risk of wound dehiscence, local infection, and scarring can be exacerbated in these approaches, including in diabetic and obese individuals. This study reports the efficacy and quality of tissue repair upon photothermal sealing of full-thickness incisional skin wounds using silk fibroin-based laser-activated sealants (LASEs) containing copper chloride salt (Cu-LASE) or silver nanoprisms (AgNPr-LASE), which absorb and convert near-infrared (NIR) laser energy to heat. LASE application results in rapid and effective skin sealing in healthy, immunodeficient, as well as diabetic and obese mice. Although lower recovery of epidermal structure and function was seen with AgNPr-LASE sealing, likely because of the hyperthermia induced by laser and presence of this material in the wound space, this approach resulted in higher enhancement in recovery of skin biomechanical strength compared to sutures and Cu-LASEs in diabetic, obese mice. Histological and immunohistochemical analyses revealed that AgNPr-LASEs resulted in significantly lower neutrophil migration to the wound compared to Cu-LASEs and sutures, indicating a more muted inflammatory response. Cu-LASEs resulted in local tissue toxicity likely because of effects of copper ions as manifested in the form of a significant epidermal gap and a 'depletion zone', which was a region devoid of viable cells proximal to the wound. Compared to sutures, LASE-mediated sealing, in later stages of healing, resulted in increased angiogenesis and diminished myofibroblast activation, which can be indicative of lower scarring. AgNPr-LASE loaded with vancomycin, an antibiotic drug, significantly lowered methicillin-resistant Staphylococcus aureus (MRSA) load in a pathogen challenge model in diabetic and obese mice and also reduced post-infection inflammation of tissue compared to antibacterial sutures. Taken together, these attributes indicate that AgNPr-LASE demonstrated a more balanced quality of tissue sealing and repair in diabetic and obese mice and can be used for combating local infections, that can result in poor healing in these individuals.

11.
J Biomed Mater Res A ; 111(9): 1372-1378, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-36951217

RESUMEN

Metabolites are not only involved in energy pathways but can also act as signaling molecules. Herein, we demonstrate that polyesters of alpha-ketoglutararte (paKG) can be generated by reacting aKG with aliphatic diols of different lengths, which release aKG in a sustained manner. paKG polymer-based microparticles generated via emulsion-evaporation technique lead to faster keratinocyte wound closures in a scratch assay test. Moreover, paKG microparticles also led to faster wound healing responses in an excisional wound model in live mice. Overall, this study shows that paKG MPs that release aKG in a sustained manner can be used to develop regenerative therapeutic responses.


Asunto(s)
Ácidos Cetoglutáricos , Polímeros , Animales , Ratones , Ácidos Cetoglutáricos/farmacología , Ácidos Cetoglutáricos/metabolismo , Poliésteres , Cicatrización de Heridas
12.
Bioeng Transl Med ; 8(2): e10412, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36925709

RESUMEN

Injuries caused by surgical incisions or traumatic lacerations compromise the structural and functional integrity of skin. Immediate approximation and robust repair of skin are critical to minimize occurrences of dehiscence and infection that can lead to impaired healing and further complication. Light-activated skin sealing has emerged as an alternative to sutures, staples, and superficial adhesives, which do not integrate with tissues and are prone to scarring and infection. Here, we evaluate both shorter- and longer-term efficacy of tissue repair response following laser-activated sealing of full-thickness skin incisions in immunocompetent mice and compare them to the efficacy seen with sutures. Laser-activated sealants (LASEs) in which, indocyanine green was embedded within silk fibroin films, were used to form viscous pastes and applied over wound edges. A hand-held, near-infrared laser was applied over the incision, and conversion of the light energy to heat by the LASE facilitated rapid photothermal sealing of the wound in approximately 1 min. Tissue repair with LASEs was evaluated using functional recovery (transepidermal water loss), biomechanical recovery (tensile strength), tissue visualization (ultrasound [US] and photoacoustic imaging [PAI]), and histology, and compared with that seen in sutures. Our studies indicate that LASEs promoted earlier recovery of barrier and mechanical function of healed skin compared to suture-closed incisions. Visualization of sealed skin using US and PAI indicated integration of the LASE with the tissue. Histological analyses of LASE-sealed skin sections showed reduced neutrophil and increased proresolution macrophages on Days 2 and 7 postclosure of incisions, without an increase in scarring or fibrosis. Together, our studies show that simple fabrication and application methods combined with rapid sealing of wound edges with improved histological outcomes make LASE a promising alternative for management of incisional wounds and lacerations.

13.
J Med Chem ; 66(10): 6836-6848, 2023 05 25.
Artículo en Inglés | MEDLINE | ID: mdl-37191470

RESUMEN

Bioactive NHC-transition metal complexes have shown promise as anti-cancer agents, but their potential use as radiosensitizers has been neglected so far. We disclose here a new series of bimetallic platinum(II) complexes displaying NHC-type bridging ligands, (bis-NHC)[trans-Pt(RNH2)I2]2, that have been synthesized via a simple, two-step procedure. They display cytotoxicity in the micromolar range on cancerous cell lines, accumulate in cells, and bind to genomic DNA, by inducing DNA damages. Notably, these bimetallic complexes demonstrate significant radiosensitizing effects on both ovarian cells A2780 and nonsmall lung carcinoma cells H1299. Further investigations revealed that bimetallic species make irradiation-induced DNA damages more persistent by inhibiting repair mechanisms. Indeed, a higher and persistent accumulation of both γ-H2AX and 53BP1 foci post-irradiation was detected, in the presence of the NHC-Pt complexes. Overall, we provide the first in vitro evidence for the radiosensitizing properties of NHC-platinum complexes, which suggests their potential use in combined chemo-radio therapy protocols.


Asunto(s)
Neoplasias Ováricas , Fármacos Sensibilizantes a Radiaciones , Humanos , Femenino , Platino (Metal)/farmacología , Aminas , Línea Celular Tumoral , Fármacos Sensibilizantes a Radiaciones/farmacología
14.
Biomater Sci ; 9(10): 3791-3803, 2021 May 18.
Artículo en Inglés | MEDLINE | ID: mdl-33876069

RESUMEN

Surgical-site infections (SSIs) occur in 2-5% of patients undergoing surgery in the US alone, impacting 300 000-500 000 lives each year, and presenting up to 11 times greater risk of death compared to patients without SSIs. The most common cause of SSI is Staphylococcus aureus, and methicillin-resistant S. aureus (MRSA) is the most common pathogen in community hospitals. Current clinical devices used for approximating incisions and traumatic lacerations include sutures, adhesives, tapes, or staples with or without antimicrobial incorporation. However, current closure technologies may not provide adequate protection against infection, are susceptible to wound dehiscence, and can result in delayed biomechanical recoveries. Laser-activated tissue repair is a sutureless technique in which chromophore-loaded sealants convert laser light energy to heat in order to induce rapid tissue sealing. Here, we describe the generation and evaluation of laser-activated sealant (LASE) biomaterials, in which, indocyanine green (ICG), an FDA-approved dye, was embedded in a silk fibroin matrix and cast into films as wound sealants. Silk-ICG films were subjected to different near-infrared (NIR) laser powers to identify temperatures optimal for laser sealing of soft tissues. A mathematical model was developed in order to determine the photothermal conversion efficiency of LASEs following laser irradiation. NIR laser activation of silk-ICG LASEs increased the recovery of skin biomechanical strength compared to sutured skin in full-thickness incisional wounds in immunocompetent mice, and live animal imaging indicated persistence of silk-ICG LASEs over several days. LASEs loaded with the antibiotic vancomycin demonstrated higher efficacies for combating MRSA infections in a mouse model of surgical site infection compared to antibacterial sutures. Our results demonstrate that LASEs can be loaded with antimicrobial drugs and may serve as new multifunctional biomaterials for rapid tissue sealing, repair and surgical site protection following surgery.


Asunto(s)
Antiinfecciosos , Staphylococcus aureus Resistente a Meticilina , Animales , Antibacterianos/uso terapéutico , Humanos , Rayos Láser , Ratones , Infección de la Herida Quirúrgica/prevención & control
15.
Metallomics ; 13(6)2021 06 12.
Artículo en Inglés | MEDLINE | ID: mdl-34021581

RESUMEN

Pt-ttpy (tolyl terpyridin-Pt complex) covalently binds to G-quadruplex (G4) structures in vitro and to telomeres in cellulo via its Pt moiety. Here, we identified its targets in the human genome, in comparison to Pt-tpy, its derivative without G4 affinity, and cisplatin. Pt-ttpy, but not Pt-tpy, induces the release of the shelterin protein TRF2 from telomeres concomitantly to the formation of DNA damage foci at telomeres but also at other chromosomal locations. γ-H2AX chromatin immunoprecipitation (ChIP-seq) after treatment with Pt-ttpy or cisplatin revealed accumulation in G- and A-rich tandemly repeated sequences, but not particularly in potential G4 forming sequences. Collectively, Pt-ttpy presents dual targeting efficiency on DNA, by inducing telomere dysfunction and genomic DNA damage at specific loci.


Asunto(s)
Cisplatino/farmacología , Daño del ADN , G-Cuádruplex , Compuestos Organoplatinos/farmacología , Neoplasias Ováricas/patología , Telómero/efectos de los fármacos , Proteína 2 de Unión a Repeticiones Teloméricas/metabolismo , Antineoplásicos/farmacología , Apoptosis , Proliferación Celular , Femenino , Humanos , Compuestos Organoplatinos/química , Neoplasias Ováricas/tratamiento farmacológico , Neoplasias Ováricas/genética , Proteína 2 de Unión a Repeticiones Teloméricas/genética , Células Tumorales Cultivadas
16.
Biochimie ; 177: 108-116, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32835734

RESUMEN

The prevalence of substrate cross-reactivity between AHL acylases and ß-lactam acylases provides a glimpse of probable links between quorum sensing and antibiotic resistance in bacteria. Both these enzyme classes belong to the N-terminal nucleophile (Ntn)-hydrolase superfamily. Penicillin V acylases alongside bile salt hydrolases constitute the cholylglycine hydrolase (CGH) group of the Ntn-hydrolase superfamily. Here we report the ability of two acylases, Slac1 and Slac2, from the marine bacterium Shewanella loihica-PV4 to hydrolyze AHLs. Three-dimensional structure of Slac1reveals the conservation of the Ntn hydrolase fold and CGH active site, making it a unique CGH exclusively active on AHLs. Slac1homologs phylogenetically cluster separate from reported CGHs and AHL acylases, thereby representing a functionally distinct sub-class of CGH that might have evolved as an adaptation to the marine environment. We hypothesize that Slac1 could provide the structural framework for understanding this subclass, and further our understanding of the evolutionary link between AHL acylases and ß-lactam acylases.


Asunto(s)
Acil-Butirolactonas/química , Acil-Butirolactonas/metabolismo , Amidohidrolasas/química , Amidohidrolasas/metabolismo , Shewanella/enzimología , Amidohidrolasas/genética , Ácidos y Sales Biliares/metabolismo , Dominio Catalítico , Pruebas de Enzimas , Modelos Moleculares , Filogenia , Estructura Cuaternaria de Proteína , Alineación de Secuencia , Shewanella/genética , Especificidad por Sustrato , beta-Lactamas/metabolismo
17.
ACS Appl Mater Interfaces ; 12(25): 27951-27960, 2020 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-32459949

RESUMEN

Copper ions play an important role in several physiological processes, including angiogenesis, growth factor induction and extracellular matrix remodeling, that modulate wound healing and tissue repair. In this work, copper-loaded alginate fibers were generated and used as surgical sutures for repair of incisional wounds in live mice. Approximately 95% of initially loaded copper ions were released from the sutures within the first 24 h following an initial burst release. This localized delivery of copper at the incision site resulted in significantly higher recovery in tissue biomechanical strengths compared to conventional nylon and calcium alginate sutures at early times following surgery. Irradiation of copper alginate sutures with near-infrared light resulted in a robust photothermal response and led to efficacies similar to those seen with nonirradiated sutures. Histopathology and immunohistological analyses indicated significantly reduced epithelial gap and higher number of CD31+ cells, which is indicative of increased angiogenesis around the incision site. Delivery of copper ions did not result in toxicity under the conditions employed. Our findings demonstrate that delivery of ionic copper from sutures resulted in efficacious approximation and healing of incisional wounds, and copper-eluting fibers may have translational potential for accelerating repair in surgical and trauma wounds.


Asunto(s)
Cobre/química , Cobre/farmacología , Alginatos/química , Animales , Células Cultivadas , Masculino , Ratones , Neovascularización Fisiológica/efectos de los fármacos , Molécula-1 de Adhesión Celular Endotelial de Plaqueta/metabolismo , Piel/citología , Suturas , Cicatrización de Heridas/efectos de los fármacos
18.
J Med Case Rep ; 13(1): 238, 2019 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-31370890

RESUMEN

BACKGROUND: Choroidal osteoma is rare clinical entity of unknown etiology, characterized by formation of mature cancellous bone within the choroid. It typically affects young females, with no racial predilection. Vision loss occurs mainly due to photoreceptor degeneration secondary to decalcification and/or development of choroidal neovascularization especially if located at the subfoveal area. CASE PRESENTATION: Our case is 9-year-old Indian (Indo-Aryan) boy identified incidentally with clinical features suggestive of choroidal osteoma with marked diminution of vision. Spectral domain optical coherence tomography demonstrated high reflectivity from the choroid and atrophy of the overlying retinal layers and B-scan ultrasound demonstrated multiple highly reflective calcified lesions within the choroid. CONCLUSION: Although available literature shows that the occurrence of this rare clinical entity is more commonly seen in young females, our case report has shown that it may be seen at a very early age. The treatment options are still not available if significant atrophy of retinal pigment epithelium has already occurred; however, vision loss due to associated choroidal neovascularization may be treated with currently available treatment options. In our case, the vision loss was due to the significant atrophy of the retinal layers. Choroidal neovascularization was not seen and our patient was advised to attend follow-up regularly.


Asunto(s)
Neoplasias de la Coroides/patología , Osteoma/patología , Niño , Neoplasias de la Coroides/diagnóstico por imagen , Femenino , Angiografía con Fluoresceína , Humanos , Masculino , Osteoma/diagnóstico por imagen , Tomografía de Coherencia Óptica , Trastornos de la Visión/diagnóstico , Trastornos de la Visión/etiología
19.
Heliyon ; 5(5): e01587, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-31193317

RESUMEN

The twin-arginine translocase (Tat) pathway transports folded proteins across the plasma membrane and plays a critical role in protein transport in haloarchaea. Computational analysis and previous experimental evidence suggested that the Tat pathway transports almost the entire secretome in haloarchaea. The TatC, receptor component of this pathway shows greater variation in membrane topology in haloarchaea than in other organisms. The presence of a unique fourteen-transmembrane TatC homolog (TatCt) in haloarchaea, over and above the expected TatC topological variants, indicates a strong correlation between the additional homologs and the large number of substrates transported via the haloarchaeal Tat pathway. Various combinations of TatC homologs with different topologies-TatCo, TatCt, TatCn, and TatCx have been observed in haloarchaea. In this report, on the basis of these combinations we have segregated all haloarchaeal Tat substrates into two groups. The first group consists of substrates that are transported by TatCt alone, whereas the second group consists of substrates that are transported by the other TatC homologs (TatCo, TatCn, and TatCx). The various haloarchaea TatA components also shows the possible segregation towards the substrates. We have also identified the possible homologs for Tat substrate chaperones, which act as a quality-control mechanism for proper protein folding. Further sequence analysis implies that the two TatC domains of TatCt complement each other's functionally. Substrate analysis also revealed subtle differences between the substrates being transported by various homologs: further experimental analysis is therefore required for better understanding of the complexities of the haloarchaeal Tat pathway.

20.
Adv Healthc Mater ; 8(14): e1900084, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-31066511

RESUMEN

Sutures are typically the primary means of soft tissue repair in surgery and trauma. Despite their widespread use, sutures do not result in immediate sealing of approximated tissues, which can result in bacterial infection and leakage. Nonabsorbable sutures and staples can be traumatic to tissue, and the trauma can be exacerbated by their subsequent removal. Use of cyanoacrylate glues is limited because of their brittleness and toxicity. In this work, laser-activated tissue-integrating sutures (LATIS) are described as novel nanodevices for soft tissue approximation and repair. Incorporation of gold nanorods within fibers generated from collagen result in LATIS fibers which demonstrate robust photothermal responses following irradiation with near infrared laser light. Compared to conventional sutures, LATIS fibers result in greater biomechanical recovery of incised skin in a mouse model of skin closure after spine surgeries. Histopathology analyses show improved repair of the epidermal gap in skin, which indicate faster tissue recovery using LATIS. The studies indicate that LATIS-facilitated approximation of skin in live mice synergizes the benefits of conventional suturing and laser-activated tissue integration, resulting in new approaches for faster sealing, tissue repair, and healing.


Asunto(s)
Luz , Nanotecnología/instrumentación , Suturas , Animales , Materiales Biocompatibles/química , Humanos , Rayos Láser , Ratones , Ratones Endogámicos BALB C , Células 3T3 NIH , Ratas , Piel/efectos de la radiación , Cicatrización de Heridas/efectos de la radiación
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