Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 45
Filtrar
1.
Adv Funct Mater ; 33(1)2023 Jan 03.
Artículo en Inglés | MEDLINE | ID: mdl-36714167

RESUMEN

Fast healing of diabetic wounds remains a major clinical challenge. Herein, this work reports a strategy to combine nanofiber aerogels containing precision macrochannels and the LL-37-mimic peptide W379 for rapid diabetic wound healing. Nanofiber aerogels consisting of poly(glycolide-co-lactide) (PGLA 90:10)/gelatin and poly-p-dioxanone (PDO)/gelatin short electrospun fiber segments were prepared by partially anisotropic freeze-drying, crosslinking, and sacrificial templating with three-dimensional (3D)-printed meshes, exhibiting nanofibrous architecture and precision micro-/macrochannels. Like human cathelicidin LL-37, W379 peptide at a concentration of 3 µg/mL enhanced the migration and proliferation of keratinocytes and dermal fibroblasts in a cell scratch assay and a proliferation assay. In vivo studies show that nanofiber aerogels with precision macrochannels can greatly promote cell penetration compared to aerogels without macrochannels. Relative to control and aerogels with and without macrochannels, adding W379 peptides to aerogels with precision macrochannels shows the best efficacy in healing diabetic wounds in mice in terms of cell infiltration, neovascularization, and re-epithelialization. The fast re-epithelization could be due to upregulation of phospho-extracellular signal-regulated kinase (p38 MAPK) after treatment with W379. Together, the approach developed in this work could be promising for the treatment of diabetic wounds and other chronic wounds.

2.
Nano Lett ; 21(3): 1508-1516, 2021 02 10.
Artículo en Inglés | MEDLINE | ID: mdl-33501831

RESUMEN

Following the COVID-19 outbreak, swabs for biological specimen collection were thrust to the forefront of healthcare materials. Swab sample collection and recovery are vital for reducing false negative diagnostic tests, early detection of pathogens, and harvesting DNA from limited biological samples. In this study, we report a new class of nanofiber swabs tipped with hierarchical 3D nanofiber objects produced by expanding electrospun membranes with a solids-of-revolution-inspired gas foaming technique. Nanofiber swabs significantly improve absorption and release of proteins, cells, bacteria, DNA, and viruses from solutions and surfaces. Implementation of nanofiber swabs in SARS-CoV-2 detection reduces the false negative rates at two viral concentrations and identifies SARS-CoV-2 at a 10× lower viral concentration compared to flocked and cotton swabs. The nanofiber swabs show great promise in improving test sensitivity, potentially leading to timely and accurate diagnosis of many diseases.


Asunto(s)
Prueba de COVID-19/instrumentación , COVID-19/diagnóstico , Nanofibras , SARS-CoV-2 , COVID-19/virología , Prueba de COVID-19/métodos , Prueba de COVID-19/estadística & datos numéricos , Reacciones Falso Negativas , Humanos , Ensayo de Materiales , Microscopía Electrónica de Rastreo , Nanofibras/ultraestructura , Nanotecnología , SARS-CoV-2/aislamiento & purificación , Manejo de Especímenes/instrumentación , Manejo de Especímenes/métodos , Manejo de Especímenes/estadística & datos numéricos
3.
Adv Funct Mater ; 30(49)2020 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-34326714

RESUMEN

The healing of large bone defects represents a clinical challenge, often requiring some form of grafting. Three-dimensional (3D) nanofiber aerogels could be a promising bone graft due to their biomimetic morphology and controlled porous structures and composition. miR-26a has been reported to induce the differentiation of bone marrow-derived mesenchymal stem cells (BMSCs) and facilitate bone formation. Introducing miR-26a with a suitable polymeric vector targeting BMSCs could improve and enhance the functions of 3D nanofiber aerogels for bone regeneration. Herein, we first developed the comb-shaped polycation (HA-SS-PGEA) carrying a targeting component, biocleavable groups and short ethanolamine (EA)-decorated poly(glycidyl methacrylate) (PGMA) (abbreviated as PGEA) arms as miR-26a delivery vector. We then assessed the cytotoxicity and transfection efficiency of this polycation and cellular response to miR-26a-incorporated nanoparticles (NPs) in vitro. HA-SS-PGEA exhibited a stronger ability to transport miR-26a and exert its functions than the gold standard polyethyleneimine (PEI) and low-molecular-weight linear PGEA. We finally examined the efficacy of HA-SS-PGEA/miR-26a NPs loaded 3D hybrid nanofiber aerogels showing a positive effect on the cranial bone defect healing. Together, the combination of 3D nanofiber aerogels and functional NPs consisting of a biodegradable and targeting polycation and therapeutic miRNA could be a promising approach for bone regeneration.

4.
Small ; 16(19): e1907393, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32212416

RESUMEN

Minimally invasive therapies avoiding surgical complexities evoke great interest in developing injectable biomedical devices. Herein, a versatile approach is reported for engineering injectable and biomimetic nanofiber microspheres (NMs) with tunable sizes, predesigned structures, and desired compositions via gas bubble-mediated coaxial electrospraying. The sizes and structures of NMs are controlled by adjusting processing parameters including air flow rate, applied voltage, distance, and spinneret configuration in the coaxial setup. Importantly, unlike the self-assembly method, this technique can be used to fabricate NMs from any material feasible for electrospinning or other nanofiber fabrication techniques. To demonstrate the versatility, open porous NMs are successfully fabricated that consist of various short nanofibers made of poly(ε-caprolactone), poly(lactic-co-glycolic acid), gelatin, methacrylated gelatin, bioglass, and magneto-responsive polymer composites. Open porous NMs support human neural progenitor cell growth in 3D with a larger number and more neurites than nonporous NMs. Additionally, highly open porous NMs show faster cell infiltration and host tissue integration than nonporous NMs after subcutaneous injection to rats. Such a novel class of NMs holds great potential for many biomedical applications such as tissue filling, cell and drug delivery, and minimally invasive tissue regeneration.


Asunto(s)
Nanofibras , Animales , Biomimética , Gelatina , Microesferas , Poliésteres , Polímeros , Ratas , Ingeniería de Tejidos , Andamios del Tejido
5.
Nanomedicine ; 22: 102081, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-31400571

RESUMEN

Biomimetic and injectable nanofiber microspheres (NMs) could be ideal candidate for minimally invasive tissue repair. Herein, we report a facile approach to fabricate peptide-tethered NMs by combining electrospinning, electrospraying, and surface conjugation techniques. The composition and size of NMs can be tuned by varying the processing parameters during the fabrication. Further, bone morphogenic protein-2 (BMP-2) and vascular endothelial growth factor (VEGF) mimicking peptides have been successfully tethered onto poly(ε-caprolactone) (PCL):gelatin:(gelatin-methacryloyl) (GelMA)(1:0.5:0.5) NMs through photocrosslinking of the methacrylic group in GelMA and octenyl alanine (OCTAL) in the modified peptides. The BMP-2-OCTAL peptide-tethered NMs significantly promote osteogenic differentiation of bone marrow-derived stem cells (BMSCs). Moreover, human umbilical vein endothelial cells (HUVECs) seeded on VEGF mimicking peptide QK-OCTAL-tethered NMs significantly up-regulated vascular-specific proteins, leading to microvascularization. The strategy developed in this work holds great potential in developing a biomimetic and injectable carrier to efficiently direct cellular response (Osteogenesis and Angiogenesis) for tissue repair.


Asunto(s)
Materiales Biomiméticos/farmacología , Inyecciones , Células Madre Mesenquimatosas/citología , Microesferas , Nanofibras/química , Péptidos/farmacología , Animales , Proteína Morfogenética Ósea 2/farmacología , Diferenciación Celular/efectos de los fármacos , Diferenciación Celular/genética , Gelatina/farmacología , Células Endoteliales de la Vena Umbilical Humana/efectos de los fármacos , Humanos , Cinética , Luz , Células Madre Mesenquimatosas/efectos de los fármacos , Microvasos/efectos de los fármacos , Microvasos/metabolismo , Nanofibras/ultraestructura , Neovascularización Fisiológica/efectos de los fármacos , Osteogénesis/efectos de los fármacos , Osteogénesis/genética , Osteopontina/metabolismo , Poliésteres/farmacología , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ingeniería de Tejidos
6.
Biomacromolecules ; 17(1): 20-31, 2016 Jan 11.
Artículo en Inglés | MEDLINE | ID: mdl-26636723

RESUMEN

Smart delivery system of photosensitizer chlorin e6 (Ce6) has been developed for targeted photodynamic therapy (PDT). Simple self-assemblies of the mixtures comprising soybean lecithin derived phosphatidylcholine (PC), phosphatidylethanolamine-poly(L-histidine)40 (PE-p(His)40), and folic acid (FA) conjugated phosphatidylethanolamine-poly(N-isopropylacrylamide)40 (PE-p(NIPAM)40-FA) in different ratios yield smart nanospheres characterized by (i) stable and uniform particle size (∼100 nm), (ii) positive surface charge, (iii) high hydrophobic drug (Ce6) loading efficiency up to 45%, (iv) covalently linked targeting moiety, (v) low cytotoxicity, and (vi) smartness showing p(His) block oriented pH and p(NIPAM) oriented temperature responsiveness. The Ce6-encapsulated vesicular nanospheres (Ce6@VNS) were used to confirm the efficiency of cellular uptake, intracellular distribution, and phototoxicity against KB tumor cells compared to free Ce6 at different temperature and pH conditions. The Ce6@VNS system showed significant photodynamic therapeutic efficiency on KB cells than free Ce6. A receptor-mediated inhibition study proved the site-specific delivery of Ce6 in targeted tumor cells.


Asunto(s)
Nanosferas/administración & dosificación , Nanosferas/química , Neoplasias/tratamiento farmacológico , Polímeros/administración & dosificación , Polímeros/química , Acrilamidas/química , Línea Celular Tumoral , Clorofilidas , Histidina/química , Humanos , Células KB , Fotoquimioterapia/métodos , Fármacos Fotosensibilizantes/química , Porfirinas/química
7.
Macromol Rapid Commun ; 35(9): 888-94, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24596253

RESUMEN

Biocompatible lipo-histidine hybrid materials conjugated with IR820 dye show pH-sensitivity, efficient intracellular delivery of doxorubicin (Dox), and intrinsic targetability to cancer cells. These new materials form highly uniform Dox-loaded nanosized vesicles via a self-assembly process showing good stability under physiological conditions. The Dox-loaded micelles are effective for suppressing MCF-7 tumors, as demonstrated in vitro and in vivo. The combined mechanisms of the EPR effect, active internalization, endosomal-triggered release, and drug escape from endosomes, and a long blood circulation time, clearly prove that the IR820 lipopeptide DDS is a safe theranostic agent for imaging-guided cancer therapy.


Asunto(s)
Histidina/química , Concentración de Iones de Hidrógeno , Humanos , Células MCF-7 , Microscopía Electrónica de Transmisión
8.
Artículo en Inglés | MEDLINE | ID: mdl-38970426

RESUMEN

Significance: Sterility and reduction of the bioburden are crucial for healing in chronic wounds such as diabetic foot ulcers. Although there are methods for measuring bioburdens, such as semiquantitative analysis of swab/biopsy samples, microbiological sampling, and molecular diagnostics, these tools are less accessible owing to costs or not being as quick as other methods. These methods are also dependent on clinical assessment by the clinician, and high bacterial burden may appear asymptomatic. Recent Advances: Autofluorescence (AF) imaging is a novel technology for identifying and quantifying chronic inhibitory bacterial load in chronic wounds. Eighty-seven percent of bacteria that frequent chronic wounds have fluorophores that fluoresce under violet light as red or cyan, depending on the type of fluorophore. Therefore, AF image-guided treatment is becoming increasingly effective for physicians to implement wound dressing changes and debridement because bacterial burdens are difficult to locate clinically. Critical Issue: Products such as the commercially available MolecuLight i:X and MolecuLight DX function as handheld cameras for physicians to use as a reference but require additional work to ensure that the photograph will be taken with adequate lighting. Future Directions: Designs for Vision Inc. introduced a device called REVEAL, an AF imaging form factor that allows the device to be worn on top of a pair of glasses, which the physician would wear intraoperatively. The benefits of this form factor include not requiring certain lighting conditions and not having to interpret the results using a handheld camera, allowing the device to be used during active surgical debridement.

9.
J Mater Chem B ; 12(11): 2818-2830, 2024 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-38411556

RESUMEN

Personalized bone-regenerative materials have attracted substantial interest in recent years. Modern clinical settings demand the use of engineered materials incorporating patient-derived cells, cytokines, antibodies, and biomarkers to enhance the process of regeneration. In this work, we formulated short microfiber-reinforced hydrogels with platelet-rich fibrin (PRF) to engineer implantable multi-material core-shell bone grafts. By employing 3D bioprinting technology, we fabricated a core-shell bone graft from a hybrid composite hydroxyapatite-coated poly(lactic acid) (PLA) fiber-reinforced methacryolyl gelatin (GelMA)/alginate hydrogel. The overall concept involves 3D bioprinting of long bone mimic microstructures that resemble a core-shell cancellous-cortical structure, with a stiffer shell and a softer core with our engineered biomaterial. We observed a significantly enhanced stiffness in the hydrogel scaffold incorporated with hydroxyapatite (HA)-coated PLA microfibers compared to the pristine hydrogel construct. Furthermore, HA non-coated PLA microfibers were mixed with PRF and GelMA/alginate hydrogel to introduce a slow release of growth factors which can further enhance cell maturation and differentiation. These patient-specific bone grafts deliver cytokines and growth factors with distinct spatiotemporal release profiles to enhance tissue regeneration. The biocompatible and bio-responsive bone mimetic core-shell multi-material structures enhance osteogenesis and can be customized to have materials at a specific location, geometry, and material combination.


Asunto(s)
Hidrogeles , Osteogénesis , Humanos , Hidrogeles/química , Durapatita , Gelatina/química , Alginatos/química , Citocinas , Poliésteres
10.
Trends Biotechnol ; 42(5): 631-647, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38158307

RESUMEN

Electrospinning technology has garnered wide attention over the past few decades in various biomedical applications including drug delivery, cell therapy, and tissue engineering. This technology can create nanofibers with tunable fiber diameters and functionalities. However, the 2D membrane nature of the nanofibers, as well as the rigidity and low porosity of electrospun fibers, lower their efficacy in tissue repair and regeneration. Recently, new avenues have been explored to resolve the challenges associated with 2D electrospun nanofiber membranes. This review discusses recent trends in creating different electrospun nanofiber microstructures from 2D nanofiber membranes by using various post-processing methods, as well as their biotechnological applications.


Asunto(s)
Biotecnología , Nanofibras , Ingeniería de Tejidos , Nanofibras/química , Biotecnología/métodos , Ingeniería de Tejidos/métodos , Sistemas de Liberación de Medicamentos , Humanos , Materiales Biocompatibles/química , Andamios del Tejido/química
11.
Nat Commun ; 15(1): 1080, 2024 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-38316777

RESUMEN

The structure and design flexibility of aerogels make them promising for soft tissue engineering, though they tend to come with brittleness and low elasticity. While increasing crosslinking density may improve mechanics, it also imparts brittleness. In soft tissue engineering, resilience against mechanical loads from mobile tissues is paramount. We report a hybrid aerogel that consists of self-reinforcing networks of micro- and nanofibers. Nanofiber segments physically entangle microfiber pillars, allowing efficient stress distribution through the intertwined fiber networks. We show that optimized hybrid aerogels have high specific tensile moduli (~1961.3 MPa cm3 g-1) and fracture energies (~7448.8 J m-2), while exhibiting super-elastic properties with rapid shape recovery (~1.8 s). We demonstrate that these aerogels induce rapid tissue ingrowth, extracellular matrix deposition, and neovascularization after subcutaneous implants in rats. Furthermore, we can apply them for engineering soft tissues via minimally invasive procedures, and hybrid aerogels can extend their versatility to become magnetically responsive or electrically conductive, enabling pressure sensing and actuation.


Asunto(s)
Nanofibras , Resiliencia Psicológica , Ratas , Animales , Nanofibras/química , Elasticidad , Ingeniería de Tejidos/métodos
12.
Adv Mater ; 36(16): e2307328, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38288789

RESUMEN

Chronic wounds resulting from diabetes, pressure, radiation therapy, and other factors continue to pose significant challenges in wound healing. To address this, this study introduces a novel hybrid fibroin fibrous scaffold (FFS) comprising randomly arranged fibroin fibers and vertically aligned cryogel fibers (CFs). The fibroin scaffold is efficiently degummed at room temperature and simultaneously formed a porous structure. The aligned CFs are produced via directional freeze-drying, achieved by controlling solution concentration and freezing polymerization temperature. The incorporation of aligned CFs into the expanded fibroin fiber scaffold leads to enhanced cell infiltration both in vitro and in vivo, further elevating the hybrid scaffold's tissue compatibility. The anti-inflammatory peptide 1 (AP-1) is also conjugated to the hybrid fibrous scaffold, effectively transforming the inflammatory status of chronic wounds from pro-inflammatory to pro-reparative. Consequently, the FFS-AP1+CF group demonstrates superior granulation tissue formation, angiogenesis, collagen deposition, and re-epithelialization during the proliferative phase compared to the commercial product PELNAC. Moreover, the FFS-AP1+CF group displays epidermis thickness, number of regenerated hair follicles, and collagen density closer to normal skin tissue. These findings highlight the potential of random fibroin fibers/aligned CFs hybrid fibrous scaffold as a promising approach for skin tissue filling and tissue regeneration.


Asunto(s)
Fibroínas , Fibroínas/química , Criogeles , Cicatrización de Heridas , Colágeno , Andamios del Tejido/química , Antiinflamatorios , Seda
13.
Acta Biomater ; 184: 81-97, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38908416

RESUMEN

The use of decellularized extracellular matrix products in tissue regeneration is quite alluring yet practically challenging due to the limitations of its availability, harsh processing techniques, and host rejection. Scaffolds obtained by either incorporating extracellular matrix (ECM) material or coating the surface can resolve these challenges to some extent. However, these scaffolds lack the complex 3D network formed by proteins and growth factors observed in natural ECM. This study introduces an approach utilizing 3D nanofiber scaffolds decorated with dECM to enhance cellular responses and promote tissue regeneration. Notably, the dECM can be customized according to specific cellular requirements, offering a tailored environment for enhanced therapeutic outcomes. Two types of 3D expanded scaffolds, namely radially aligned scaffolds (RAS) and laterally expanded scaffolds (LES) fabricated by the gas-foaming expansion were utilized. To demonstrate the proof-of-concept, human dermal fibroblasts (HDFs) seeded on these scaffolds for up to 8 weeks, resulted in uniform and highly aligned cells which deposited ECM on the scaffolds. These cellular components were then removed from the scaffolds through decellularization (e.g., SDS treatment and freeze-thaw cycles). The dECM-decorated 3D expanded nanofiber scaffolds can direct and support cell alignment and proliferation along the underlying fibers upon recellularization. An in vitro inflammation assay indicates that dECM-decorated LES induces a lower immune response than dECM-decorated RAS. Further, subcutaneous implantation of dECM-decorated RAS and LES shows higher cell infiltration and angiogenesis within 7 and 14 days than RAS and LES without dECM decoration. Taken together, dECM-decorated 3D expanded nanofiber scaffolds hold great potential in tissue regeneration and tissue modeling. STATEMENT OF SIGNIFICANCE: Decellularized ECM scaffolds have attained widespread attention in biomedical applications due to their intricate 3D framework of proteins and growth factors. Mimicking such a complicated architecture is a clinical challenge. In this study, we developed natural ECM-decorated 3D electrospun nanofiber scaffolds with controlled alignments to mimic human tissue. Fibroblasts were cultured on these scaffolds for 8 weeks to deposit natural ECM and decellularized by either freeze-thawing or detergent to obtain decellularized ECM scaffolds. These scaffolds were tested in both in-vitro and in-vivo conditions. They displayed higher cellular attributes with lower immune response making them a good grafting tool in tissue regeneration.


Asunto(s)
Matriz Extracelular Descelularizada , Fibroblastos , Nanofibras , Regeneración , Andamios del Tejido , Andamios del Tejido/química , Nanofibras/química , Humanos , Fibroblastos/citología , Fibroblastos/metabolismo , Matriz Extracelular Descelularizada/química , Matriz Extracelular Descelularizada/farmacología , Animales , Ingeniería de Tejidos/métodos , Matriz Extracelular/química , Proliferación Celular/efectos de los fármacos , Ratones
14.
ACS Omega ; 9(8): 9765-9781, 2024 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-38434900

RESUMEN

Copper-cystine-based high aspect ratio structures (CuHARS) possess exceptional physical and chemical properties and exhibit remarkable biodegradability in human physiological conditions. Extensive testing has confirmed the biocompatibility and biodegradability of CuHARS under diverse biological conditions, making them a viable source of essential Cu2+. These ions are vital for catalyzing the production of nitric oxide (NO) from the decomposition of S-nitrosothiols (RSNOs) found in human blood. The ability of CuHARS to act as a Cu2+ donor under specific concentrations has been demonstrated in this study, resulting in the generation of elevated levels of NO. Consequently, this dual function makes CuHARS effective as both a bactericidal agent and a promoter of angiogenesis. In vitro experiments have shown that CuHARS actively promotes the migration and formation of complete lumens by redirecting microvascular endothelial cells. To maximize the benefits of CuHARS, they have been incorporated into biomimetic electrospun poly(ε-caprolactone)/gelatin nanofiber aerogels. Through the regulated release of Cu2+ and NO production, these channeled aerogels not only provide antibacterial support but also promote angiogenesis. Taken together, the inclusion of CuHARS in biomimetic scaffolds could hold great promise in revolutionizing tissue regeneration and wound healing.

15.
Biomacromolecules ; 14(5): 1434-43, 2013 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-23627834

RESUMEN

A series of dual stimuli responsive synthetic polymer bioconjugate chimeric materials, poly(N-isopropylacrylamide)55-block-poly(L-histidine)n [p(NIPAM)55-b-p(His)n] (n=50, 75, 100, 125), have been synthesized by employing reversible addition-fragmentation chain transfer polymerization of NIPAM, followed by ring-opening polymerization of α-amino acid N-carboxyanhydrides. The dual stimuli responsive properties of the resulting biocompatiable and membrenolytic p(NIPAM)55-b-p(His)n polymers are investigated for their use as a stimuli responsive drug carrier for tumor targeting. Highly uniform self-assembled micelles (∼55 nm) fabricated by p(NIPAM)55-b-p(His)n polymers display sharp thermal and pH responses in aqueous media. An anticancer drug, doxorubicin (Dox), is effectively encapsulated in the micelles and the controlled Dox release is investigated in different temperature and pH conditions. Antitumor effect of the released Dox is also assessed using the HepG2 human hepatocellular carcinoma cell lines. Dox molecules released from the [p(NIPAM)55-b-p(His)n] micelles remain biologically active and have stimuli responsive capability to kill cancer cells. The self-assembling ability of these hybrid materials into uniform micelles and their efficiency to encapsulate Dox makes them a promising drug carrier to cancer cells. The new chimeric materials thus display tunable properties that can make them useful for a molecular switching device and controlled drug delivery applications needing responses to temperature and pH for the improvement of cancer chemotherapy.


Asunto(s)
Resinas Acrílicas/síntesis química , Antibióticos Antineoplásicos/administración & dosificación , Doxorrubicina/administración & dosificación , Portadores de Fármacos/síntesis química , Proteínas/síntesis química , Resinas Acrílicas/farmacología , Antibióticos Antineoplásicos/farmacología , Supervivencia Celular/efectos de los fármacos , Preparaciones de Acción Retardada , Doxorrubicina/farmacología , Portadores de Fármacos/farmacología , Células Hep G2 , Humanos , Concentración de Iones de Hidrógeno , Cinética , Micelas , Proteínas/farmacología , Temperatura
16.
Biomater Sci ; 11(3): 949-963, 2023 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-36537259

RESUMEN

Hemorrhage is the leading cause of death following battlefield injuries. Although several hemostats are commercially available, they do not meet all the necessary requirements to stop bleeding in combat injuries. Here, we engineer thermoresponsive shear-thinning hydrogels (T-STH) composed of a thermoresponsive polymer, poly(N-isopropyl acrylamide) (p(NIPAM)), and hemostatic silicate nanodisks, LAPONITE®, as minimally invasive injectable hemostatic agents. Our T-STH is a physiologically stable hydrogel that can be easily injected through a syringe and needle and exhibits rapid mechanical recovery. Additionally, it demonstrates temperature-dependent blood coagulation owing to the phase transition of p(NIPAM). It decreases in vitro blood clotting times over 50% at physiological temperatures compared to room temperature. Furthermore, it significantly prevents blood loss in an ex vivo bleeding model at different blood flow rates (1 mL min-1 and 5 mL min-1) by forming a wound plug. More importantly, our T-STH is comparable to a commercially available hemostat, Floseal, in terms of blood loss and blood clotting time in an in vivo rat liver bleeding model. Furthermore, once the hemorrhage is stabilized, our T-STH can be easily removed using a cold saline wash without any rebleeding or leaving any residues. Taken together, our T-STH can be used as a first aid hemostat to treat external hemorrhages in emergency situations.


Asunto(s)
Hemostáticos , Hidrogeles , Ratas , Animales , Hidrogeles/química , Hemorragia , Coagulación Sanguínea , Hemostáticos/uso terapéutico , Polímeros
17.
Adv Mater ; 35(5): e2207335, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36444871

RESUMEN

Drawing inspiration for biomaterials from biological systems has led to many biomedical innovations. One notable bioinspired device, Velcro, consists of two substrates with interlocking ability. Generating reversibly interlocking biomaterials is an area of investigation, as such devices can allow for modular tissue engineering, reversibly interlocking biomaterial interfaces, or friction-based coupling devices. Here, a biaxially interlocking interface generated using electrostatic flocking is reported. Two electrostatically flocked substrates are mechanically and reversibly interlocked with the ability to resist shearing and compression forces. An initial high-throughput screen of polyamide flock fibers with varying diameters and fiber lengths is conducted to elucidate the roles of different fiber parameters on scaffold mechanical properties. After determining the most desirable parameters via weight scoring, polylactic acid (PLA) fibers are used to emulate the ideal scaffold for in vitro use. PLA flocked scaffolds are populated with osteoblasts and interlocked. Interlocked flocked scaffolds improved cell survivorship under mechanical compression and sustained cell viability and proliferation. Additionally, the compression and shearing resistance of cell-seeded interlocking interfaces increased with increasing extracellular matrix deposition. The introduction of extracellular matrix-reinforced interlocking interfaces may serve as binders for modular tissue engineering, act as scaffolds for engineering tissue interfaces, or enable friction-based couplers for biomedical applications.


Asunto(s)
Materiales Biocompatibles , Andamios del Tejido , Andamios del Tejido/química , Materiales Biocompatibles/química , Ingeniería de Tejidos , Poliésteres/química , Matriz Extracelular/química
18.
Bioact Mater ; 20: 137-163, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-35663339

RESUMEN

Natural bone constitutes a complex and organized structure of organic and inorganic components with limited ability to regenerate and restore injured tissues, especially in large bone defects. To improve the reconstruction of the damaged bones, tissue engineering has been introduced as a promising alternative approach to the conventional therapeutic methods including surgical interventions using allograft and autograft implants. Bioengineered composite scaffolds consisting of multifunctional biomaterials in combination with the cells and bioactive therapeutic agents have great promise for bone repair and regeneration. Cellulose and its derivatives are renewable and biodegradable natural polymers that have shown promising potential in bone tissue engineering applications. Cellulose-based scaffolds possess numerous advantages attributed to their excellent properties of non-toxicity, biocompatibility, biodegradability, availability through renewable resources, and the low cost of preparation and processing. Furthermore, cellulose and its derivatives have been extensively used for delivering growth factors and antibiotics directly to the site of the impaired bone tissue to promote tissue repair. This review focuses on the various classifications of cellulose-based composite scaffolds utilized in localized bone drug delivery systems and bone regeneration, including cellulose-organic composites, cellulose-inorganic composites, cellulose-organic/inorganic composites. We will also highlight the physicochemical, mechanical, and biological properties of the different cellulose-based scaffolds for bone tissue engineering applications.

19.
Mil Med Res ; 10(1): 16, 2023 03 28.
Artículo en Inglés | MEDLINE | ID: mdl-36978167

RESUMEN

Biomimetic materials have emerged as attractive and competitive alternatives for tissue engineering (TE) and regenerative medicine. In contrast to conventional biomaterials or synthetic materials, biomimetic scaffolds based on natural biomaterial can offer cells a broad spectrum of biochemical and biophysical cues that mimic the in vivo extracellular matrix (ECM). Additionally, such materials have mechanical adaptability, microstructure interconnectivity, and inherent bioactivity, making them ideal for the design of living implants for specific applications in TE and regenerative medicine. This paper provides an overview for recent progress of biomimetic natural biomaterials (BNBMs), including advances in their preparation, functionality, potential applications and future challenges. We highlight recent advances in the fabrication of BNBMs and outline general strategies for functionalizing and tailoring the BNBMs with various biological and physicochemical characteristics of native ECM. Moreover, we offer an overview of recent key advances in the functionalization and applications of versatile BNBMs for TE applications. Finally, we conclude by offering our perspective on open challenges and future developments in this rapidly-evolving field.


Asunto(s)
Materiales Biocompatibles , Materiales Biomiméticos , Humanos , Materiales Biocompatibles/farmacología , Materiales Biocompatibles/uso terapéutico , Materiales Biocompatibles/química , Ingeniería de Tejidos , Medicina Regenerativa , Biomimética , Materiales Biomiméticos/farmacología , Materiales Biomiméticos/uso terapéutico , Materiales Biomiméticos/química
20.
ChemNanoMat ; 8(7)2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35990019

RESUMEN

Electrospun nanofibers show great potential in biomedical applications. This mini review article traces the recent advances in electrospun nanofibers for wound management via various approaches. Initially, we provide a short note on the four phases of wound healing, including hemostasis, inflammation, proliferation, and remodeling. Then, we state how the nanofiber dressings can stop bleeding and reduce the pain. Following that, we discuss the delivery of therapeutics and cells using different types of nanofibers for enhancing cell migration, angiogenesis, and re-epithelialization, resulting in the promotion of wound healing. Finally, we present the conclusions and future perspectives regarding the use of electrospun nanofibers for wound management.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA