Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 28
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Nature ; 630(8016): 360-367, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38778109

RESUMO

Implanted biomaterials and devices face compromised functionality and efficacy in the long term owing to foreign body reactions and subsequent formation of fibrous capsules at the implant-tissue interfaces1-4. Here we demonstrate that an adhesive implant-tissue interface can mitigate fibrous capsule formation in diverse animal models, including rats, mice, humanized mice and pigs, by reducing the level of infiltration of inflammatory cells into the adhesive implant-tissue interface compared to the non-adhesive implant-tissue interface. Histological analysis shows that the adhesive implant-tissue interface does not form observable fibrous capsules on diverse organs, including the abdominal wall, colon, stomach, lung and heart, over 12 weeks in vivo. In vitro protein adsorption, multiplex Luminex assays, quantitative PCR, immunofluorescence analysis and RNA sequencing are additionally carried out to validate the hypothesis. We further demonstrate long-term bidirectional electrical communication enabled by implantable electrodes with an adhesive interface over 12 weeks in a rat model in vivo. These findings may offer a promising strategy for long-term anti-fibrotic implant-tissue interfaces.


Assuntos
Materiais Biocompatíveis , Fibrose , Reação a Corpo Estranho , Próteses e Implantes , Adesivos Teciduais , Animais , Feminino , Humanos , Masculino , Camundongos , Ratos , Parede Abdominal , Adsorção , Materiais Biocompatíveis/química , Colo , Eletrodos Implantados , Fibrose/patologia , Fibrose/prevenção & controle , Reação a Corpo Estranho/prevenção & controle , Reação a Corpo Estranho/patologia , Coração , Pulmão , Camundongos Endogâmicos C57BL , Especificidade de Órgãos , Reação em Cadeia da Polimerase , Ratos Sprague-Dawley , Estômago , Suínos , Fatores de Tempo , Adesivos Teciduais/química , Imunofluorescência , Reprodutibilidade dos Testes , Análise de Sequência de RNA
2.
Nat Mater ; 22(7): 895-902, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37322141

RESUMO

Owing to the unique combination of electrical conductivity and tissue-like mechanical properties, conducting polymer hydrogels have emerged as a promising candidate for bioelectronic interfacing with biological systems. However, despite the recent advances, the development of hydrogels with both excellent electrical and mechanical properties in physiological environments is still challenging. Here we report a bi-continuous conducting polymer hydrogel that simultaneously achieves high electrical conductivity (over 11 S cm-1), stretchability (over 400%) and fracture toughness (over 3,300 J m-2) in physiological environments and is readily applicable to advanced fabrication methods including 3D printing. Enabled by these properties, we further demonstrate multi-material 3D printing of monolithic all-hydrogel bioelectronic interfaces for long-term electrophysiological recording and stimulation of various organs in rat models.


Assuntos
Hidrogéis , Polímeros , Animais , Ratos , Condutividade Elétrica , Impressão Tridimensional
3.
Proc Natl Acad Sci U S A ; 117(27): 15497-15503, 2020 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-32576692

RESUMO

Bioadhesives such as tissue adhesives, hemostatic agents, and tissue sealants have potential advantages over sutures and staples for wound closure, hemostasis, and integration of implantable devices onto wet tissues. However, existing bioadhesives display several limitations including slow adhesion formation, weak bonding, low biocompatibility, poor mechanical match with tissues, and/or lack of triggerable benign detachment. Here, we report a bioadhesive that can form instant tough adhesion on various wet dynamic tissues and can be benignly detached from the adhered tissues on demand with a biocompatible triggering solution. The adhesion of the bioadhesive relies on the removal of interfacial water from the tissue surface, followed by physical and covalent cross-linking with the tissue surface. The triggerable detachment of the bioadhesive results from the cleavage of bioadhesive's cross-links with the tissue surface by the triggering solution. After it is adhered to wet tissues, the bioadhesive becomes a tough hydrogel with mechanical compliance and stretchability comparable with those of soft tissues. We validate in vivo biocompatibility of the bioadhesive and the triggering solution in a rat model and demonstrate potential applications of the bioadhesive with triggerable benign detachment in ex vivo porcine models.


Assuntos
Materiais Biocompatíveis/química , Hidrogéis/química , Ferida Cirúrgica/terapia , Adesivos Teciduais/química , Adesividade , Animais , Reagentes de Ligações Cruzadas/química , Modelos Animais de Doenças , Feminino , Teste de Materiais , Ratos , Bicarbonato de Sódio/química , Soluções , Succinimidas/química , Suínos , Técnicas de Fechamento de Ferimentos/instrumentação
4.
Int J Cancer ; 148(6): 1470-1477, 2021 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-33034052

RESUMO

To compare the efficacy and safety of radiotherapy (RT) and chemotherapy of pegaspargase, gemcitabine, cisplatin and dexamethasone (DDGP) combined with RT in newly diagnosed stage I-II natural killer/T-cell lymphoma (NKTL), we designed a randomized, controlled, open-label, multicenter clinical trial. Data from 65 stage I-II NKTL patients whose diagnoses were confirmed using immunohistochemistry were enrolled from January 2011 to December 2013 in the First Affiliated Hospital of Zhengzhou University. Patients were randomly divided into the RT group (n = 35) and the DDGP combined with RT group (n = 30). There was a difference between the Eastern Cooperative Oncology Group (ECOG) score in the two arms (P = .013). The complete response rate (CRR) and objective response rate (ORR) of DDGP combined with RT group were superior to those in the RT group (CRR: 73.3% vs 48.6%; ORR: 83.3% vs 60.0%, respectively). The 5-year progression-free survival (PFS) rate and overall survival (OS) rate in the DDGP combined with RT group were higher than those in the RT group (82.9% vs 56.5% for PFS, P = .023; 85.7% vs 60.4% for OS, P = .040), and treatment methods and lactate dehydrogenase were independent risk factors. Myelosuppression (P < .001), gastrointestinal reactions (P < .001), abnormal liver function (P = .007), coagulation abnormalities (P < .001) and baldness (P < .001) were more likely to occur in the DDGP combined with RT group. In conclusion, DDGP combined with radiotherapy obviously obtained great efficacy and prolonged the survival time of patients, also the side effects were mild for stage I-II NKTL. This trial was registered at https://register.clinicaltrials.gov as #NCT01501136.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Quimiorradioterapia/métodos , Linfoma Extranodal de Células T-NK/tratamento farmacológico , Linfoma Extranodal de Células T-NK/radioterapia , Adolescente , Adulto , Idoso , Asparaginase/administração & dosagem , Cisplatino/administração & dosagem , Desoxicitidina/administração & dosagem , Desoxicitidina/análogos & derivados , Dexametasona/administração & dosagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Polietilenoglicóis/administração & dosagem , Intervalo Livre de Progressão , Adulto Jovem , Gencitabina
5.
Appl Microbiol Biotechnol ; 104(17): 7437-7455, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32666187

RESUMO

Acute liver failure is a clinical emergency associated with high mortality. Accumulating evidence indicates that gut microbiota participates in the progression of liver injury, and preventive therapies based on altering gut microbiota are of great interest. Previous studies demonstrated that Lactobacillus salivarius LI01 attenuates hepatic injury, though efficiency in curtailed in the harsh environment in the gastrointestinal tract. In this study, a system to encapsulate LI01 in alginate-pectin (AP) microgels was investigated. Encapsulation significantly enhances probiotic viability for long-term storage and heat treatment, and in simulated gastrointestinal fluids (SGF or SIF) and bile salt solutions. Acute liver injury was induced in Sprague-Dawley (SD) rats by D-galactosamine (D-GaIN) injection following pretreatment with probiotics. Liver and gut barrier function, cytokines, liver and gut histology, bacterial translocation, and gut microbiota were assessed. Administration of encapsulated LI01 more effectively upregulates hepatic anti-inflammatory cytokine IL-10 and TLR-3, restores expressions of gut barrier biomarkers Claudin-1 and MUC2 and attenuates destruction of mucosal ultrastructure compared with unencapsulated probiotics pretreatment. Pretreatment with AP-LI01 microgels altered the microbial community, decreasing the abundance of pathogenic taxa Ruminiclostridium, Dorea and Ruminococcaceae_UCG-004 and enriching beneficial taxa Ruminococcaceae_UCG-014, Eubacterium, and Prevotella_1 that produce short-chain fatty acids. These results suggest that AP encapsulation of LI01 boosts viability and attenuates liver injury by reducing inflammation and restoring intestinal barrier function. These beneficial effects are probably due to alternation of gut flora. These findings provide new insight into encapsulation technology and prevention of liver failure. KEY POINTS: • Alginate-pectin encapsulation enhances the viability of Lactobacillus salivarius LI01 under simulated commercial conditions and simulated gastrointestinal environment. • AP-LI01 microgel attenuates hepatic and intestinal inflammation and restores gut barrier function. • AP-LI01 microgel alters gut microbial community with increased SCFAs producers and decreased pathogenic microbes. • Beneficial improvements after administration of probiotics are highly associated with alternation of gut microbial community.


Assuntos
Ligilactobacillus salivarius , Microgéis , Probióticos , Alginatos , Animais , Galactosamina , Fígado , Pectinas , Ratos , Ratos Sprague-Dawley
6.
J Exp Bot ; 66(8): 2271-81, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25873671

RESUMO

Plant 14-3-3 proteins are phosphoserine-binding proteins that regulate a wide array of targets via direct protein-protein interactions. In this study, the role of a 14-3-3 protein, GRF9, in plant response to water stress was investigated. Arabidopsis wild-type, GRF9-deficient mutant (grf9), and GRF9-overexpressing (OE) plants were treated with polyethylene glycol (PEG) to induce mild water stress. OE plant showed better whole-plant growth and root growth than the wild type under normal or water stress conditions while the grf9 mutant showed worse growth. In OE plants, GRF9 favours the allocation of shoot carbon to roots. In addition, GRF9 enhanced proton extrusion, mainly in the root elongation zone and root hair zone, and maintained root growth under mild water stress. Grafting among the wild type, OE, and grf9 plants showed that when OE plants were used as the scion and GRF9 was overexpressed in the shoot, it enhanced sucrose transport into the root, and when OE plants were used as rootstock and GRF9 was overexpressed in the root, it caused more release of protons into the root surface under water stress. Taken together, the results suggest that under PEG-induced water stress, GRF9 is involved in allocating more carbon from the shoot to the root and enhancing proton secretion in the root growing zone, and this process is important for root response to mild water stress.


Assuntos
Proteínas 14-3-3/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/fisiologia , Raízes de Plantas/crescimento & desenvolvimento , Polietilenoglicóis/farmacologia , Arabidopsis/efeitos dos fármacos , Arabidopsis/enzimologia , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/genética , Transporte Biológico/efeitos dos fármacos , Biomassa , Metabolismo dos Carboidratos/efeitos dos fármacos , Desidratação , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Glucosiltransferases/metabolismo , Floema/efeitos dos fármacos , Floema/metabolismo , Raízes de Plantas/anatomia & histologia , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Plantas Geneticamente Modificadas , ATPases Translocadoras de Prótons/metabolismo , Prótons , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Sintase do Amido/metabolismo , Sacarose/metabolismo
7.
Ann Hematol ; 93(11): 1889-94, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24923454

RESUMO

The prognosis of extranodal nature killer (NK)/T cell lymphoma (ENKL) is dismal because of its aggressive course and multidrug resistance. Currently, for patients with relapsed/refractory ENKL, L-asparaginase-based regimens such as L-asparaginase, ifosfamide, methotrexate, etoposide, and dexamethasone (SMILE) or L-asparaginase, methotrexate, and dexamethasone (AspaMetDex) are recommended. We retrospectively investigated the efficacy and safety of gemcitabine, pegaspargase, cisplatin, and dexamethasone (DDGP) combination chemotherapy in the treatment of 17 relapsed/refractory ENKL patients. Clinical data from these patients were collected and analyzed. The primary end point was overall response rate (ORR). All patients were subjected to 2 to 6 cycles of DDGP chemotherapy, and the median number of cycles of DDGP regimen administrated was four. The ORR was 88.2 % (15/17), with nine patients (52.9 %) achieved complete response (CR) and six patients (35.3 %) achieved partial response (PR). The median follow-up time was 17 months (range 2-28 months). The 1-year overall survival (OS) rate and 1-year progression-free survival (PFS) were 82.4 and 64.7 %, respectively. For those CR responders, the median PFS was 17 months. Grade 3/4 neutropenia occurred in nine patients (52.9 %) and grade 3/4 thrombocytopenia occurred in six patients (35.3 %). DDGP combination chemotherapy produces favorable outcomes in relapsed/refractory ENKL, and more attention should be paid to treatment-related myelosuppression. Further prospective trials are expected to define the efficacy.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Linfoma Extranodal de Células T-NK/diagnóstico , Linfoma Extranodal de Células T-NK/tratamento farmacológico , Recidiva Local de Neoplasia/diagnóstico , Recidiva Local de Neoplasia/tratamento farmacológico , Adolescente , Adulto , Idoso , Asparaginase/administração & dosagem , Cisplatino/administração & dosagem , Estudos de Coortes , Desoxicitidina/administração & dosagem , Desoxicitidina/análogos & derivados , Dexametasona/administração & dosagem , Feminino , Humanos , Linfoma Extranodal de Células T-NK/mortalidade , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/mortalidade , Polietilenoglicóis/administração & dosagem , Recidiva , Estudos Retrospectivos , Taxa de Sobrevida/tendências , Resultado do Tratamento , Adulto Jovem , Gencitabina
8.
Carbohydr Polym ; 327: 121679, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38171689

RESUMO

Management of noncompressible torso hemorrhage is an urgent clinical requirement, desiring biomaterials with rapid hemostasis, anti-infection and excellent resilient properties. In this research, we have prepared a highly resilient cryogel with both hemostatic and antibacterial effects by chemical crosslinking and electrostatic interaction. The network structure crosslinked by quaternized chitosan and genipin was interspersed with oxidized bacterial cellulose after lyophilization. The as-prepared cryogel can quickly return to the original volume when soaking in water or blood. The appropriately sized pores in the cryogel help to absorb blood cells and further activate coagulation, while the quaternary ammonium salt groups on quaternized chitosan inhibit bacterial infections. Both cell and animal experiments showed that the cryogel was hypotoxic and could promote the regeneration of wound tissue. This research provides a new pathway for the preparation of double crosslinking cryogels and offers effective and safe biomaterials for the emergent bleeding management of incompressible wounds.


Assuntos
Celulose Oxidada , Quitosana , Hemostáticos , Animais , Criogéis/química , Quitosana/farmacologia , Quitosana/química , Celulose Oxidada/farmacologia , Cicatrização , Hemostáticos/farmacologia , Hemostáticos/química , Hemorragia/tratamento farmacológico , Materiais Biocompatíveis/farmacologia , Antibacterianos/farmacologia , Antibacterianos/química
9.
Nat Commun ; 15(1): 1215, 2024 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-38331971

RESUMO

Tissue adhesives are promising alternatives to sutures and staples for joining tissues, sealing defects, and immobilizing devices. However, existing adhesives mostly take the forms of glues or hydrogels, which offer limited versatility. We report a direct-ink-write 3D printable tissue adhesive which can be used to fabricate bioadhesive patches and devices with programmable architectures, unlocking new potential for application-specific designs. The adhesive is conformable and stretchable, achieves robust adhesion with wet tissues within seconds, and exhibits favorable biocompatibility. In vivo rat trachea and colon defect models demonstrate the fluid-tight tissue sealing capability of the printed patches, which maintained adhesion over 4 weeks. Moreover, incorporation of a blood-repelling hydrophobic matrix enables the printed patches to seal actively bleeding tissues. Beyond wound closure, the 3D printable adhesive has broad applicability across various tissue-interfacing devices, highlighted through representative proof-of-concept designs. Together, this platform offers a promising strategy toward developing advanced tissue adhesive technologies.


Assuntos
Adesivos Teciduais , Ratos , Animais , Adesivos Teciduais/química , Adesivos , Hidrogéis/química , Tecnologia
10.
Bioresour Technol ; 395: 130400, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38286169

RESUMO

The rational use of bamboo to make dissolving pulp can offer up new opportunities for cellulose production, alleviating wood scarcity. Bamboo contains a high content of non-fiber cells, which presents technical challenges in dissolving pulp production by the conventional process. In this study, a process concept of separating hemicelluloses is presented by fiber fractionation and purification for cleaner production of bamboo dissolving pulp: bamboo kraft pulp was fractionated into long-fiber and short-fiber fractions. The cellulose-rich long-fiber fraction was converted to dissolving pulp by further purification treatment with acid hydrolysis and cold caustic extraction. The hemicellulose-rich short-fiber fraction was used for papermaking. The laboratory results were confirmed by those from mill trials. The combined pulp yield (dissolving pulp + paper-grade pulp) reached 49 %, which was significantly higher than that of the conventional pre-hydrolysis kraft pulping process. Furthermore, the quality of dissolving pulp was higher due to inherently higher cellulose content of long-fiber fraction.


Assuntos
Celulose , Fracionamento Químico , Madeira , Hidrólise
11.
Biomater Adv ; 153: 213566, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37536027

RESUMO

Triple-negative breast cancer (TNBC) is always the most challenging breast cancer subtype. Herein, brucine, encapsulated in peptide-modified liposomes, was proposed for treating TNBC by transdermal delivery. For the TD peptide-modified brucine-loaded liposome (Bru-TD-Lip) we developed, it presents high encapsulation efficiency of brucine and stability. In vitro, Bru-TD-Lip shows the enhanced percutaneous permeability of brucine, is able to readily enter TNBC cells, and significantly inhibits the proliferation, migration, and invasion of these cells. In vivo, through transdermal delivery, Bru-TD-Lip presents good biosafety and anti-tumor efficacy. The transdermal delivery of Bru-TD-Lip effectively targets and inhibits subcutaneous mammary carcinogenesis in female nude mice. Compared with oral administration, the transdermal delivery significantly reduces the damage of brucine to major organs and enhances the antitumor outcomes of brucine in treating TNBC. This study provides a new therapeutic strategy for treating triple-negative breast cancer by brucine.


Assuntos
Lipossomos , Neoplasias de Mama Triplo Negativas , Humanos , Camundongos , Animais , Feminino , Lipossomos/uso terapêutico , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Camundongos Nus , Peptídeos/uso terapêutico
12.
Ear Nose Throat J ; : 1455613221106218, 2022 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-35737853

RESUMO

Ameloblastomas are slow-growing, aggressive odontogenic epithelial tumors that originate from the jawbone. One of the most easily relapsing maxillofacial tumors, ameloblastomas mainly occur in the mandibular molar area and ascending branch, although they can occasionally occur in the nasal cavity and paranasal sinuses. A 14-year-old child with autism spectrum disorder underwent sinus computed tomography (CT) under anesthesia. A swollen tumor had grown in the left maxillary sinus, and the bone of the maxillary sinus was damaged. Nine months after the first operation, recurrence was observed in the left maxillary sinus. The pathological diagnosis was ameloblastoma. Due to the child's inability to communicate and cooperate with the treatment normally, he underwent endoscopic surgery again combined with low-temperature plasma treatment. No tumor recurrence was found on reexamination 6 months after surgery.

13.
Curr Med Sci ; 42(6): 1240-1247, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36462132

RESUMO

OBJECTIVE: This study aimed to investigate the effect of combretastatin A4 phosphate (CA4P) on proliferation, migration, and capillary tube formation of human umbilical vein endothelial cells (HUVECs) and the efficacy of transcatheter arterial embolization combined with CA4P in the treatment of rabbit VX2 liver tumor. METHODS: The effects of different concentrations of CA4P on proliferation, migration and capillary tube formation of HUVECs were investigated by cell proliferation assay, wound healing assay and capillary tube formation assay, respectively. Thirty-two rabbits implanted with liver VX2 tumors were randomly divided into 4 groups. After catheterization of the left hepatic artery, the infusion was performed using normal saline (group A), CA4P aqueous solution (group B), lipiodol and polyvinyl alcohol particles (group C), and CA4P lipiodol emulsion and polyvinyl alcohol particles (group D), respectively. Half of the animals in each group were euthanized for immunohistochemical analysis to evaluate microvessel density (MVD) at 3 days post-treatment. The other half were examined by MRI and histology to evaluate tumor growth and necrosis at 7 days post-treatment. RESULTS: CA4P could inhibit the proliferation, migration, and tube formation of HUVECs in cell experiments. After interventional treatment, the level of MVD in group D was lower than that in group C (P<0.01). The tumor volume in group C or D was lower than that in group A or B (P<0.01). The tumor necrosis rate was higher in group D than in the other groups. CONCLUSION: The study suggests that CA4P could inhibit the proliferation, migration, and capillary tube formation of HUVECs, and transcatheter arterial embolization combined with CA4P could inhibit the growth of VX2 tumor and obviously induce tumor necrosis.


Assuntos
Antineoplásicos Fitogênicos , Embolização Terapêutica , Neoplasias Hepáticas , Animais , Coelhos , Antineoplásicos Fitogênicos/farmacologia , Óleo Etiodado/uso terapêutico , Células Endoteliais da Veia Umbilical Humana , Neoplasias Hepáticas/patologia , Modelos Animais , Necrose , Neovascularização Patológica/tratamento farmacológico , Neovascularização Patológica/patologia , Álcool de Polivinil/uso terapêutico
14.
Sci Transl Med ; 14(630): eabh2857, 2022 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-35108064

RESUMO

Surgical sealing and repair of injured and resected gastrointestinal (GI) organs are critical requirements for successful treatment and tissue healing. Despite being the standard of care, hand-sewn closure of GI defects using sutures faces limitations and challenges. In this work, we introduce an off-the-shelf bioadhesive GI patch capable of atraumatic, rapid, robust, and sutureless repair of GI defects. The GI patch integrates a nonadhesive top layer and a dry, bioadhesive bottom layer, resulting in a thin, flexible, transparent, and ready-to-use patch with tissue-matching mechanical properties. The rapid, robust, and sutureless sealing capability of the GI patch is systematically characterized using ex vivo porcine GI organ models. In vitro and in vivo rat models are used to evaluate the biocompatibility and degradability of the GI patch in comparison to commercially available tissue adhesives (Coseal and Histoacryl). To validate the GI patch's efficacy, we demonstrate successful sutureless in vivo sealing and healing of GI defects in rat colon, stomach, and small intestine as well as in porcine colon injury models. The proposed GI patch provides a promising alternative to suture for repair of GI defects and offers potential clinical opportunities for the repair of other organs.


Assuntos
Procedimentos Cirúrgicos sem Sutura , Adesivos Teciduais , Animais , Ratos , Estômago , Suínos , Adesivos Teciduais/farmacologia , Adesivos Teciduais/uso terapêutico , Cicatrização
15.
Nat Biomed Eng ; 6(10): 1118-1133, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35788686

RESUMO

Diabetic foot ulcers and other chronic wounds with impaired healing can be treated with bioengineered skin or with growth factors. However, most patients do not benefit from these treatments. Here we report the development and preclinical therapeutic performance of a strain-programmed patch that rapidly and robustly adheres to diabetic wounds, and promotes wound closure and re-epithelialization. The patch consists of a dried adhesive layer of crosslinked polymer networks bound to a pre-stretched hydrophilic elastomer backing, and implements a hydration-based shape-memory mechanism to mechanically contract diabetic wounds in a programmable manner on the basis of analytical and finite-element modelling. In mouse and human skin, and in mini-pigs and humanized mice, the patch enhanced the healing of diabetic wounds by promoting faster re-epithelialization and angiogenesis, and the enrichment of fibroblast populations with a pro-regenerative phenotype. Strain-programmed patches might also be effective for the treatment of other forms of acute and chronic wounds.


Assuntos
Diabetes Mellitus , Pé Diabético , Humanos , Animais , Camundongos , Suínos , Porco Miniatura , Cicatrização , Pé Diabético/tratamento farmacológico , Pé Diabético/metabolismo , Elastômeros , Polímeros/uso terapêutico
16.
Adv Mater ; 33(11): e2007667, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33522062

RESUMO

For decades, bioadhesive materials have garnered great attention due to their potential to replace sutures and staples for sealing tissues during minimally invasive surgical procedures. However, the complexities of delivering bioadhesives through narrow spaces and achieving strong adhesion in fluid-rich physiological environments continue to present substantial limitations to the surgical translation of existing sealants. In this work, a new strategy for minimally invasive tissue sealing based on a multilayer bioadhesive patch, which is designed to repel body fluids, to form fast, pressure-triggered adhesion with wet tissues, and to resist biofouling and inflammation is introduced. The multifunctional patch is realized by a synergistic combination of three distinct functional layers: i) a microtextured bioadhesive layer, ii) a dynamic, blood-repellent hydrophobic fluid layer, and iii) an antifouling zwitterionic nonadhesive layer. The patch is capable of forming robust adhesion to tissue surfaces in the presence of blood, and exhibits superior resistance to bacterial adhesion, fibrinogen adsorption, and in vivo fibrous capsule formation. By adopting origami-based fabrication strategies, it is demonstrated that the patch can be readily integrated with a variety of minimally invasive end effectors to provide facile tissue sealing in ex vivo porcine models, offering new opportunities for minimally invasive tissue sealing in diverse clinical scenarios.


Assuntos
Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Adesivos Teciduais , Animais , Hemostáticos , Suínos
17.
Biomaterials ; 273: 120807, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33848730

RESUMO

Previous preclinical and clinical studies have shown that using only a single therapy makes it difficult to completely eradicate tumors and restrain cancer metastasis. To overcome this challenge, multi-modal synergistic treatments have attracted considerable attention. Herein, an ultrathin Cu-loaded CoCuFe-selenide (CCFS) was prepared by a facile topotactic transformation from CoCuFe layered double hydroxide (LDH) nanosheets (NSs), followed by surface modification with polyvinyl pyrrolidone (PVP) and l-arginine (L-Arg). The resultant CCFS-PVP-L-Arg (CPA) system shows excellent synergetic photothermal and gas therapy (PTT/GT). The CCFS NSs have strong LSPR absorbance characteristic, with enhanced light absorption in the near-infrared (NIR) region. This endows the CPA nanocomposite with an outstanding photothermal conversion efficiency of 72.0% (pH 7.4) and 81.0% (pH 5.4), among the highest reported for 2D chalcogenide nanomaterials. In addition, NO release from CPA is triggered by decomposition of L-Arg in the H2O2-rich and acidic tumor microenvironment, permitting localized NO gas therapy in the tumor site. In vitro experiments revealed 91.8% apoptosis of HepG2 cells, and in vivo studies showed complete tumor elimination upon treatment with the CPA nanocomposite under NIR irradiation. To the best of our knowledge, this is the first report of combined defect-induced high-efficiency PTT with H2O2 and pH targeted GT.


Assuntos
Nanocompostos , Nanopartículas , Técnicas Fotoacústicas , Peróxido de Hidrogênio , Fototerapia , Terapia Fototérmica , Povidona
18.
Nat Biomed Eng ; 5(10): 1131-1142, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34373600

RESUMO

Tissue adhesives do not normally perform well on tissues that are covered with blood or other bodily fluids. Here we report the design, adhesion mechanism and performance of a paste that haemostatically seals tissues in less than 15 s, independently of the blood-coagulation rate. With a design inspired by barnacle glue (which strongly adheres to wet and contaminated surfaces owing to adhesive proteins embedded in a lipid-rich matrix), the paste consists of a blood-repelling hydrophobic oil matrix containing embedded microparticles that covalently crosslink with tissue surfaces on the application of gentle pressure. It slowly resorbs over weeks, sustains large pressures (approximately 350 mm Hg of burst pressure in a sealed porcine aorta), makes tough (interfacial toughness of 150-300 J m-2) and strong (shear and tensile strengths of, respectively, 40-70 kPa and 30-50 kPa) interfaces with blood-covered tissues, and outperforms commercial haemostatic agents in the sealing of bleeding porcine aortas ex vivo and of bleeding heart and liver tissues in live rats and pigs. The paste may aid the treatment of severe bleeding, even in individuals with coagulopathies.


Assuntos
Hemostáticos , Thoracica , Adesivos Teciduais , Animais , Ratos , Suínos , Aderências Teciduais
19.
Org Lett ; 22(7): 2564-2568, 2020 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-32181668

RESUMO

A feasible and convenient strategy for oligosaccharide synthesis, which realizes reaction in solution while product purification occurs only by solid-liquid filtration, has been developed. By using a hop-on/off carrier (polytetrafluoroethylene particle), rapid synthesis of tumor-associated antigen Globo-H hexasaccharide has been successfully achieved within 5 steps in 48% overall yield without any intermediate purification by column chromatography. Also, global deprotection, including the cleavage of the tag, proceeded simultaneously only by one-step hydrogenolysis.


Assuntos
Oligossacarídeos/síntese química , Oligossacarídeos/economia , Politetrafluoretileno/química , Configuração de Carboidratos , Oligossacarídeos/química , Fatores de Tempo
20.
ACS Appl Mater Interfaces ; 12(43): 48310-48320, 2020 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-33048540

RESUMO

Ultrathin transition metal chalcogenide (TMC) nanosheets with ultrahigh photothermal conversion efficiency (η) and excellent stability are strongly desired in the application of photothermal therapy (PTT). However, the current synthetic methods of ultrathin TMC nanosheets have issues in obtaining uniform morphology, good dispersion, and satisfactory PTT behavior. Herein, ultrathin nanosheets of CoFe-selenide (CFS) with a finely controlled structure were prepared via a topological structural transformation process from an ultrathin CoFe-layered double hydroxide (LDH) precursor, followed by surface modification with poly(ethylene glycol) (PEG). The as-prepared CFS-PEG nanosheets inherit the ultrathin morphology of CoFe-LDH and exhibit an outstanding photothermal performance with a η of 74.5%, which is the first rank level of reported two-dimensional (2D) TMC nanosheet materials. The CFS-PEG nanosheets possess a satisfactory photoacoustic (PA) imaging capability with an ultralow detection limit (5 ppm) and simultaneously superior T2 magnetic resonance imaging (MRI) performance with a large transverse MR relaxivity value (r2) of 347.7 mM-1 s-1. Moreover, in vitro and in vivo assays verify superior anticancer activity with a dramatic photoinduced cancer cell apoptosis and tumor ablation. Therefore, a successful paradigm is provided for rational design and preparation of ultrathin TMC nanosheets in this work, holding enormous potential in cancer theranostics.


Assuntos
Antineoplásicos/farmacologia , Materiais Biocompatíveis/farmacologia , Nanopartículas Metálicas/química , Metais Pesados/farmacologia , Polietilenoglicóis/farmacologia , Nanomedicina Teranóstica , Animais , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Materiais Biocompatíveis/química , Proliferação de Células/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Hidróxidos/química , Lasers , Metais Pesados/química , Camundongos , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/patologia , Tamanho da Partícula , Terapia Fototérmica , Polietilenoglicóis/química , Propriedades de Superfície , Células Tumorais Cultivadas
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA