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The absence of ears in children is a global problem. An implant made of costal cartilage is the standard procedure for ear reconstruction; however, side effects such as pneumothorax, loss of thoracic cage shape, and respiratory complications have been documented. Three-dimensional (3D) printing allows the generation of biocompatible scaffolds that mimic the shape, mechanical strength, and architecture of the native extracellular matrix necessary to promote new elastic cartilage formation. We report the potential use of a 3D-bioprinted poly-ε-caprolactone (3D-PCL) auricle-shaped framework seeded with remaining human microtia chondrocytes for the development of elastic cartilage for autologous microtia ear reconstruction. An in vivo assay of the neo-tissue formed revealed the generation of a 3D pinna-shaped neo-tissue, and confirmed the formation of elastic cartilage by the presence of type II collagen and elastin with histological features and a protein composition consistent with normal elastic cartilage. According to our results, a combination of 3D-PCL auricle frameworks and autologous microtia remnant tissue generates a suitable pinna structure for autologous ear reconstruction.
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BACKGROUND: Treatment of severe or chronic skin wounds is an important challenge facing medicine and a significant health care burden. Proper wound healing is often affected by bacterial infection; where biofilm formation is one of the main risks and particularly problematic because it confers protection to microorganisms against antibiotics. One avenue to prevent bacterial colonization of wounds is the use of silver nanoparticles (AgNPs); which have proved to be effective against non-multidrug-resistant and multidrug-resistant bacteria. In addition, the use of mesenchymal stem cells (MSC) is an excellent option to improve wound healing due to their capability for differentiation and release of relevant growth factors. Finally, radiosterilized pig skin (RPS) is a biomatrix successfully used as wound dressing to avoid massive water loss, which represents an excellent carrier to deliver MSC into wound beds. Together, AgNPs, RPS and MSC represent a potential dressing to control massive water loss, prevent bacterial infection and enhance skin regeneration; three essential processes for appropriate wound healing with minimum scaring. RESULTS: We synthesized stable 10 nm-diameter spherical AgNPs that showed 21- and 16-fold increase in bacteria growth inhibition (in comparison to antibiotics) against clinical strains Staphylococcus aureus and Stenotrophomonas maltophilia, respectively. RPS samples were impregnated with different AgNPs suspensions to develop RPS-AgNPs nanocomposites with different AgNPs concentrations. Nanocomposites showed inhibition zones, in Kirby-Bauer assay, against both clinical bacteria tested. Nanocomposites also displayed antibiofilm properties against S. aureus and S. maltophilia from RPS samples impregnated with 250 and 1000 ppm AgNPs suspensions, respectively. MSC were isolated from adipose tissue and seeded on nanocomposites; cells survived on nanocomposites impregnated with up to 250 ppm AgNPs suspensions, showing 35% reduction in cell viability, in comparison to cells on RPS. Cells on nanocomposites proliferated with culture days, although the number of MSC on nanocomposites at 24 h of culture was lower than that on RPS. CONCLUSIONS: AgNPs with better bactericide activity than antibiotics were synthesized. RPS-AgNPs nanocomposites impregnated with 125 and 250 ppm AgNPs suspensions decreased bacterial growth, decreased biofilm formation and were permissive for survival and proliferation of MSC; constituting promising multi-functional dressings for successful treatment of skin wounds.
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Vendajes , Biopelículas/efectos de los fármacos , Células Madre Mesenquimatosas/citología , Nanocompuestos/química , Plata/farmacología , Piel/efectos de los fármacos , Cicatrización de Heridas/efectos de los fármacos , Animales , Antiinfecciosos/farmacología , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Humanos , Inmunofenotipificación , Células Madre Mesenquimatosas/efectos de los fármacos , Nanopartículas del Metal/ultraestructura , Pruebas de Sensibilidad Microbiana , Nanocompuestos/ultraestructura , Soluciones , Esterilización , Sus scrofaRESUMEN
ZnO and Zn acetate nanoparticles were embedded in polycaprolactone coaxial-fibers and uniaxial-fibers matrices to develop potential antibacterial nanocomposite wound dressings (mats). Morphology, composition, wettability, crystallinity and fiber structure of mats were characterized. Antibacterial properties of mats were tested against E. coli and S. aureus by turbidity and MTT assays. The effect of UVA illumination (prior to bacteria inoculation) on mats' antibacterial activity was also studied. Results showed that a coaxial-fibers design maintained nanoparticles distributed in the outer-shell of fibers and, in general, enhanced the antibacterial effect of the mats, in comparison to conventional uniaxial-fibers mats. Results indicated that mats simultaneously inhibited planktonic and biofilm bacterial growth by, probably, two main antibacterial mechanisms; 1) release of Zn2+ ions (mainly from Zn acetate nanoparticles) and 2) photocatalytic oxidative processes exerted by ZnO nanoparticles. Antibacterial properties of mats were significantly improved by coaxial-fibers design and exposure to UVA-light prior to bacteria inoculation.
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Antibacterianos/administración & dosificación , Escherichia coli/efectos de los fármacos , Nanofibras/administración & dosificación , Poliésteres/química , Staphylococcus aureus/efectos de los fármacos , Acetato de Zinc/administración & dosificación , Óxido de Zinc/administración & dosificación , Antibacterianos/química , Vendajes , Escherichia coli/crecimiento & desarrollo , Nanofibras/química , Nanotecnología , Staphylococcus aureus/crecimiento & desarrollo , Acetato de Zinc/química , Óxido de Zinc/químicaRESUMEN
PURPOSE: The purpose of this study was to evaluate the clinical and sequential imaging follow-up results at a mean of 36 months after an arthroscopic technique for implantation of matrix-encapsulated autologous chondrocytes for the treatment of articular cartilage lesions on the femoral condyles. METHODS: Ten patients underwent arthroscopic implantation of autologous chondrocytes seeded onto a bioabsorbable scaffold. The patients were evaluated clinically using a visual analog scale (VAS) for pain and International Knee Documentation Committee (IKDC), Lysholm, and Tegner scores. Magnetic resonance imaging (MRI) T2-mapping and magnetic resonance observation of cartilage repair tissue (MOCART) evaluations were also performed. Second-look arthroscopic evaluation using the International Cartilage Repair Society (ICRS) grading classification was performed at 12 months. RESULTS: Compared with their preoperative values, at 36 months mean values ± standard deviation for the VAS scale for pain were 6.0 ± 1.5 to 0.3 ± 0.4. Improvement in clinical scores between preoperative values and 36-month follow-up values in subjective IKDC scores was 46.9 ± 18.5 to 77.2 ± 12.8; in Lysholm scores, it was 51.8 ± 25.1 to 87.9 ± 6.5, and in the Tegner activity scale it was 2.9 ± 1.7 to 5.9 ± 1.9. Mean T2 mapping and MOCART scores improved over time to 38.1 ± 4.4 ms and 72.5 ± 10, respectively. Mean ICRS score by second-look arthroscopy at 1 year was 10.4 ± 0.1. CONCLUSIONS: All clinical scores improved over time compared with the preoperative values. Clinical results are comparable with MRI T2 mapping and ICRS evaluations, suggesting that this arthroscopic technique for cell-based cartilage repair is efficacious and reproducible at a mean of 36 months of follow-up. LEVEL OF EVIDENCE: Level IV, therapeutic case series.
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Artroscopía/métodos , Cartílago Articular/cirugía , Condrocitos/trasplante , Articulación de la Rodilla/cirugía , Adulto , Cartílago/cirugía , Cartílago/trasplante , Femenino , Fémur , Estudios de Seguimiento , Humanos , Traumatismos de la Rodilla/cirugía , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Dimensión del Dolor/métodos , Segunda Cirugía , Andamios del Tejido , Trasplante Autólogo , Resultado del Tratamiento , Adulto JovenRESUMEN
Complete rupture of the anterior cruciate ligament (ACL) is a common problem in orthopedics. At present, there are many techniques to reconstruct ligaments, which include the use of autografts, allografts, and, in some cases, artificial ligaments. The latter have not provided good results in the short, medium, and long term. The purpose of present study was to engineer functional biological tissue that could potentially be used to replace the knee ligaments by applying tissue engineering techniques and mechanical stimulation with a bioreactor, promoting cellular differentiation and matrix synthesis. In this preliminary study, the new tissue was characterized with mechanical tests and biological tests (viability and immunochemistry), comparing their behavior with that of the native tissue. Mechanical and biological tests proved that mechanical stimulation administered with a bioreactor maintains the ligament fibroblast phenotype and promotes synthesis of the extracellular matrix.
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Reconstrucción del Ligamento Cruzado Anterior/métodos , Ligamento Cruzado Anterior/cirugía , Reactores Biológicos , Ingeniería de Tejidos/métodos , Animales , Lesiones del Ligamento Cruzado Anterior , Diferenciación Celular/fisiología , Matriz Extracelular/metabolismo , Fibroblastos/metabolismo , Técnicas In Vitro , PorcinosRESUMEN
Three-dimensional (3D) hydrogels provide tissue-like complexities and allow for the spatial orientation of cells, leading to more realistic cellular responses in pathophysiological environments. There is a growing interest in developing multifunctional hydrogels using ternary mixtures for biomedical applications. This study examined the biocompatibility and suitability of human auricular chondrocytes from microtia cultured onto steam-sterilized 3D Chitosan/Gelatin/Poly(Vinyl Alcohol) (CS/Gel/PVA) hydrogels as scaffolds for tissue engineering applications. Hydrogels were prepared in a polymer ratio (1:1:1) through freezing/thawing and freeze-drying and were sterilized by autoclaving. The macrostructure of the resulting hydrogels was investigated by scanning electron microscopy (SEM), showing a heterogeneous macroporous structure with a pore size between 50 and 500 µm. Fourier-transform infrared (FTIR) spectra showed that the three polymers interacted through hydrogen bonding between the amino and hydroxyl moieties. The profile of amino acids present in the gelatin and the hydrogel was determined by ultra-performance liquid chromatography (UPLC), suggesting that the majority of amino acids interacted during the formation of the hydrogel. The cytocompatibility, viability, cell growth and formation of extracellular matrix (ECM) proteins were evaluated to demonstrate the suitability and functionality of the 3D hydrogels for the culture of auricular chondrocytes. The cytocompatibility of the 3D hydrogels was confirmed using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, reaching 100% viability after 72 h. Chondrocyte viability showed a high affinity of chondrocytes for the hydrogel after 14 days, using the Live/Dead assay. The chondrocyte attachment onto the 3D hydrogels and the formation of an ECM were observed using SEM. Immunofluorescence confirmed the expression of elastin, aggrecan and type II collagen, three of the main components found in an elastic cartilage extracellular matrix. These results demonstrate the suitability and functionality of a CS/Gel/PVA hydrogel as a 3D support for the auricular chondrocytes culture, suggesting that these hydrogels are a potential biomaterial for cartilage tissue engineering applications, aimed at the regeneration of elastic cartilage.
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Several ocular diseases affect the corneal surface; the development of effective technologies for the treatment of corneal lesions has brought about an improvement in the quality of life of affected patients. The aim of this study is to culture and characterize limbal stem cells cultured on gamma ((60)Co) radiosterilized human amnion (RHA). Limbal stem cells were isolated from ten preserved samples of corneal transplant. The cells were cultured since primary culture until expanded cells on RHA and stained with monoclonal antibodies to establish their immunophenotype, after which cytokeratin 12 and Vimentin were positive by immunohistochemistry. The immunophenotype remained constant since primary culture until expanded cells in RHA. The RHA and cells construct were structurally integrated. Immunohistochemistry was cytokeratin 12, Vimentin positive, and cytokeratin 19 negative. In vitro limbal cells maintain a constant epithelial transition immunophenotype in culture up to primary culture until expanded cells on RHA.
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Amnios/citología , Amnios/efectos de la radiación , Técnicas de Cultivo de Célula/métodos , Rayos gamma , Limbo de la Córnea/citología , Células Madre/citología , Andamios del Tejido/química , Biomarcadores/metabolismo , Supervivencia Celular/efectos de la radiación , Células Cultivadas , Humanos , Inmunohistoquímica , Inmunofenotipificación , Células Madre/efectos de la radiación , EsterilizaciónRESUMEN
Articular cartilage is a specialized tissue that provides a smooth surface for joint movement and load transmission. Unfortunately, it has limited regenerative capacity. Tissue engineering, combining different cell types, scaffolds, growth factors, and physical stimulation has become an alternative for repairing and regenerating articular cartilage. Dental Follicle Mesenchymal Stem Cells (DFMSCs) are attractive candidates for cartilage tissue engineering because of their ability to differentiate into chondrocytes, on the other hand, the polymers blend like Polycaprolactone (PCL) and Poly Lactic-co-Glycolic Acid (PLGA) have shown promise given their mechanical properties and biocompatibility. In this work, the physicochemical properties of polymer blends were evaluated by Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscope (SEM) and were positive for both techniques. The DFMSCs demonstrated stemness by flow cytometry. The scaffold showed to be a non-toxic effect when we evaluated it with Alamar blue, and the samples were analyzed using SEM and phalloidin staining to evaluate cell adhesion to the scaffold. The synthesis of glycosaminoglycans was positive on the construct in vitro. Finally, the PCL/PLGA scaffold showed a better repair capacity than two commercial compounds, when tested in a chondral defect rat model. These results suggest that the PCL/PLGA (80:20) scaffold may be suitable for applications in the tissue engineering of articular hyaline cartilage.
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Among three-dimensional (3D) scaffold fabrication methods, porous polymers templated using high internal phase emulsions (HIPEs) have emerged as an attractive method due to the facile generation of interconnected porosity through a variety of synthetic routes. These include a bottom-up approach to selectively incorporate nanomaterials onto the inner walls in a nonaqueous environment. In this work, novel nonaqueous HIPEs made of different (meth)acrylate monomers and a deep eutectic solvent (DES) were formulated with nonfunctionalized nanohydroxyapatite (NHA), which also played the role of cosurfactant. Free radical polymerization of HIPEs yielded free-standing nanocomposites with 3D interconnected macroporosity and nonfunctionalized NHA selectively decorating the scaffolds' inner surface. The influence of different polymer functionalities, acrylate or methacrylate, their alkyl tail length, and the presence of NHA on MC3T3-E1 preosteoblast cell proliferation in vitro, reactive oxygen species (ROS) production and alkaline phosphatase (ALP) activity were evaluated. All materials presented promising biocompatibility, non-hemolytic activity, negligible inflammatory response along to remarkably enhanced cell proliferation (e.g., up to 160-fold cell proliferation increase compared with polystyrene plate) in vitro, which open the path for the development of scaffolds in regenerative medicine. It is noteworthy that polyHIPEs studied here were obtained using a green synthetic protocol where nonfunctionalized nanoparticles can be selectively incorporated into a scaffolds' inner walls. This versatile technique allows for the simple construction of 3D bioactive nanocomposite scaffolds with varied compositions for cell culture.
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Ingeniería de Tejidos , Andamios del Tejido , Proliferación Celular , Durapatita , Emulsiones , Porosidad , SolventesRESUMEN
Herein, we report the synthesis of Au nanoparticles (AuNPs) in chitosan (CTS) solution by chemically reducing HAuCl4. CTS was further functionalized with glycidyl methacrylate (chitosan-g-glycidyl methacrylate/AuNP, CTS-g-GMA/AuNP) to improve the mechanical properties for cellular regeneration requirements of CTS-g-GMA/AuNP. Our nanocomposites promote excellent cellular viability and have a positive effect on cytokine regulation in the inflammatory and anti-inflammatory response of skin cells. After 40 days of nanocomposite exposure to a skin wound, we showed that our films have a greater skin wound healing capacity than a commercial film (TheraForm®), and the presence of the collagen allows better cosmetic ave aspects in skin regeneration in comparison with a nanocomposite with an absence of this protein. Electrical percolation phenomena in such nanocomposites were used as guiding tools for the best nanocomposite performance. Our results suggest that chitosan-based Au nanocomposites show great potential for skin wound repair.
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Periodontitis is a chronic, multifactorial, inflammatory disease characterized by the progressive destruction of the periodontal tissues. Guided tissue regeneration (GTR), involving the use of barrier membranes, is one of the most successful clinical procedures for periodontal therapy. Nevertheless, rapid degradation of the membranes and membrane-related infections are considered two of the major reasons for GTR clinical failure. Recently, integration of non-antibiotic, antimicrobial materials to the membranes has emerged as a novel strategy to face the bacterial infection challenge, without increasing bacterial resistance. In this sense, bismuth subsalicylate (BSS) is a non-antibiotic, metal-based antimicrobial agent effective against different bacterial strains, that has been long safely used in medical treatments. Thus, the aim of the present work was to fabricate fibrillar, non-rapidly bioresorbable, antibacterial GTR membranes composed of polycaprolactone (PCL), gelatin (Gel), and BSS as the antibacterial agent. PCL-G-BSS membranes with three different BSS concentrations (2 wt./v%, 4 wt./v%, and 6 wt./v%) were developed by electrospinning and their morphology, composition, water wettability, mechanical properties, Bi release and degradation rate were characterized. The Cytotoxicity of the membranes was studiedin vitrousing human osteoblasts (hFOB) and gingival fibroblasts (HGF-1), and their antibacterial activity was tested againstAggregatibacter actinomycetemcomitans, Escherichia coli, Porphyromonas gingivalisandStaphylococcus aureus.The membranes obtained exhibited adequate mechanical properties for clinical application, and appropriate degradation rates for allowing periodontal defects regeneration. The hFOB and HGF-1 cells displayed adequate viability when in contact with the lixiviated products from the membranes, and, in general, displayed antibacterial activity against the four bacteria strains tested. Thus, the PCL-G-BSS membranes showed to be appropriate as potential barrier membranes for periodontal GTR treatments.
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Antibacterianos , Bismuto , Gelatina/química , Membranas Artificiales , Compuestos Organometálicos , Poliésteres/química , Salicilatos , Antibacterianos/química , Antibacterianos/farmacología , Antibacterianos/toxicidad , Materiales Biocompatibles/química , Materiales Biocompatibles/farmacología , Materiales Biocompatibles/toxicidad , Bismuto/química , Bismuto/farmacología , Bismuto/toxicidad , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Técnicas Electroquímicas , Fibroblastos/efectos de los fármacos , Encía/citología , Regeneración Tisular Guiada Periodontal , Humanos , Compuestos Organometálicos/química , Compuestos Organometálicos/farmacología , Compuestos Organometálicos/toxicidad , Salicilatos/química , Salicilatos/farmacología , Salicilatos/toxicidadRESUMEN
Objective. To evaluate minimum biosecurity parameters (MBP) for arthroscopic matrix-encapsulated autologous chondrocyte implantation (AMECI) based on patients' clinical outcomes, magnetic resonance imaging (MRI) T2-mapping, Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score, and International Cartilage Repair Society (ICRS) second-look arthroscopic evaluation, laying the basis for a future multicenter study. Design. Pilot clinical study. We analyzed the logistics to perform AMECI to treat focal chondral lesions in different hospitals following strict biosecurity parameters related to tissue and construct transportation, chondrocyte isolation, and cell expansion. Patient progress was analyzed with patient-reported outcome measures, MRI T2-mapping, MOCART, and ICRS arthroscopic second-look evaluation. Results. Thirty-five lesions in 30 patients treated in 7 different hospitals were evaluated. Cell viability before implantation was >90%. Cell viability in construct remnants was 87% ± 11% at 24 hours, 75% ± 17.1% at 48 hours, and 60% ± 8% at 72 hours after implantation. Mean final follow-up was 37 months (12-72 months). Patients showed statistically significant improvement in all clinical scores and MOCART evaluations. MRI T2-mapping evaluation showed significant decrease in relaxation time from 61.2 ± 14.3 to 42.9 ± 7.2 ms (P < 0.05). Arthroscopic second-look evaluation showed grade II "near normal" tissue in 83% of patients. Two treatment failures were documented. Conclusions. It was feasible to perform AMECI in 7 different institutions in a large metropolitan area following our biosecurity measures without any implant-related complication. Treated patients showed improvement in clinical, MRI T2-mapping, and MOCART scores, as well as a low failure rate and a favorable ICRS arthroscopic evaluation at a mid-term follow-up. Level of Evidence. 2b.
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Cartílago Articular , Condrocitos , Cartílago Articular/diagnóstico por imagen , Cartílago Articular/cirugía , Estudios de Seguimiento , Humanos , América Latina , Trasplante Autólogo/métodosRESUMEN
A novel brush-like poly(2-aminoethyl methacrylate) (PAEMA) was grafted onto chitosan (CS) through gamma radiation-induced polymerization. The copolymer (CS-g-PAEMA) was used to prepare a sodium acetate leached poly(urethane-urea) scaffold. The above derivatives were developed, synthesized, and characterized to meet the specific characteristics of biomaterials. The results revealed that this method is an easy and successful route for grafting PAEMA onto CS. The feasibility of preparing a CS-g-PAEMA polyurethane foam was confirmed by mechanical, morphometric, spectroscopic, and cytotoxic studies. The scaffold showed high biocompatibility both in vitro and in vivo. The first experiment proved that CS-based polyurethane efficiently allows the dynamic culturing of human fibroblast cells. Additionally, an in vivo study in a murine model indicated a complete integration of the scaffold to surrounding subcutaneous tissue as supported by the histological and histochemical assessments. The aforementioned results support the use of CS-g-PAEMA poly(saccharide-urethane) as a model of in vitro-engineered skin.
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Quitosano/química , Metacrilatos/química , Polímeros/química , Poliuretanos/química , Ingeniería de Tejidos/métodos , Andamios del Tejido/química , Animales , Materiales Biocompatibles/química , Fibroblastos/citología , Rayos gamma , Humanos , Espectroscopía de Resonancia Magnética/métodos , Ratones , Polimerizacion , Piel/citología , Espectroscopía Infrarroja por Transformada de Fourier/métodosRESUMEN
BACKGROUND: Few randomized controlled trials with a midterm follow-up have compared matrix-assisted autologous chondrocyte transplantation (MACT) with microfracture (MFx) for knee cartilage lesions. PURPOSE: To compare the structural, clinical, and safety outcomes at midterm follow-up of MACT versus MFx for treating symptomatic knee cartilage lesions. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: A total of 48 patients aged between 18 and 50 years, with 1- to 4-cm2 International Cartilage Repair Society (ICRS) grade III to IV knee chondral lesions, were randomized in a 1:1 ratio to the MACT and MFx treatment groups. A sequential prospective evaluation was performed using magnetic resonance imaging (MRI) T2 mapping, the MOCART (magnetic resonance observation of cartilage repair tissue) score, second-look arthroscopic surgery, patient-reported outcome measures, the responder rate (based on achieving the minimal clinically important difference for the Knee injury and Osteoarthritis Outcome Score [KOOS] pain and KOOS Sport/Recreation), adverse events, and treatment failure (defined as a reoperation because of symptoms caused by the primary defect and the detachment or absence of >50% of the repaired tissue during revision surgery). RESULTS: Overall, 35 patients (18 MACT and 17 MFx) with a mean chondral lesion size of 1.8 ± 0.8 cm2 (range, 1-4 cm2) were followed up to a mean of 6 years postoperatively (range, 4-9 years). MACT demonstrated significantly better structural outcomes than MFx at 1 to 6 years postoperatively. At final follow-up, the MRI T2 mapping values of the repaired tissue were 37.7 ± 8.5 ms for MACT versus 46.4 ± 8.5 ms for MFx (P = .003), while the MOCART scores were 59.4 ± 17.3 and 42.4 ± 16.3, respectively (P = .006). More than 50% defect filling was seen in 95% of patients at 2 years and 82% at 6 years in the MACT group and in 67% at 2 years and 53% at 6 years in the MFx group. The second-look ICRS scores at 1 year were 10.7 ± 1.3 for MACT and 9.0 ± 1.8 for MFx (P = .001). Both groups showed significant clinical improvements at 6 years postoperatively compared with their preoperative status. Significant differences favoring the MACT group were observed at 2 years on the KOOS Activities of Daily Living (P = .043), at 4 years on all KOOS subscales (except Symptoms; P < .05) and the Tegner scale (P = .008), and at 6 years on the Tegner scale (P = .010). The responder rates at 6 years were 53% and 77% for MFx and MACT, respectively. There were no reported treatment failures after MACT; the failure rate was 8.3% in the MFx group. Neither group had serious adverse events related to treatment. CONCLUSION: Patients who underwent MACT had better structural outcomes than those who underwent MFx at 1 to 6 years postoperatively. Both groups of patients showed significant clinical improvements at final follow-up compared with their preoperative status. MACT showed superiority at 4 years for the majority of the KOOS subscales and for the Tegner scale at 4 to 6 years. The MACT group also had a higher responder rate and lower failure rate at final follow-up. REGISTRATION: NCT01947374 (ClinicalTrials.gov identifier).
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Cartílago Articular , Fracturas por Estrés , Actividades Cotidianas , Adolescente , Adulto , Cartílago Articular/cirugía , Condrocitos , Estudios de Seguimiento , Humanos , Articulación de la Rodilla/cirugía , Imagen por Resonancia Magnética , Persona de Mediana Edad , Estudios Prospectivos , Trasplante Autólogo , Adulto JovenRESUMEN
Blends of natural and synthetic polymers have recently attracted great attention as scaffolds for tissue engineering applications due to their favorable biological and mechanical properties. Nevertheless, phase-separation of blend components is an important challenge facing the development of electrospun homogeneous fibrillar natural-synthetic polymers scaffolds; phase-separation can produce significant detrimental effects for scaffolds fabricated by electrospinning. In the present study, blends of gelatin (Gel; natural polymer) and polycaprolactone (PCL; synthetic polymer), containing 30 and 45 wt% Gel, were prepared using acetic acid as a 'green' sole solvent to straightforwardly produce appropriate single-step Gel-PCL solutions for electrospinning. Miscibility of Gel and PCL in the scaffolds was assessed and the morphology, chemical composition and structural and solid-state properties of the scaffolds were thoroughly investigated. Results showed that the two polymers proved miscible under the single-step solution process used and that the electrospun scaffolds presented suitable properties for potential skin tissue engineering applications. Viability, metabolic activity and protein expression of human fibroblasts cultured on the Gel-PCL scaffolds were evaluated using LIVE/DEAD (calcein/ethidium homodimer), MTT-Formazan and immunocytochemistry assays, respectively. In vitro results showed that the electrospun Gel-PCL scaffolds enhanced cell viability and proliferation in comparison to PCL scaffolds. Furthermore, scaffolds allowed fibroblasts expression of extracellular matrix proteins, tropoelastin and collagen Type I, in a similar way to positive controls. Results indicated the feasibility of the single-step solution process used herein to obtain homogeneous electrospun Gel-PCL scaffolds with Gel content ≥30 wt% and potential properties to be used as scaffolds for skin tissue engineering applications for wound healing.
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Fibroblastos/efectos de los fármacos , Gelatina/química , Poliésteres/química , Piel/efectos de los fármacos , Ingeniería de Tejidos/instrumentación , Andamios del Tejido , Supervivencia Celular , Colágeno Tipo I/metabolismo , Conductividad Eléctrica , Matriz Extracelular/metabolismo , Calor , Humanos , Concentración de Iones de Hidrógeno , Polímeros/química , Piel/metabolismo , Solventes/química , Espectrofotometría Infrarroja , Espectroscopía Infrarroja por Transformada de Fourier , Estrés Mecánico , Resistencia a la Tracción , Termogravimetría , Ingeniería de Tejidos/métodos , Tropoelastina/química , Viscosidad , Cicatrización de Heridas , Difracción de Rayos XRESUMEN
The bacterial colonization of absorbable membranes used for guided tissue regeneration (GTR), as well as their rapid degradation that can cause their rupture, are considered the major reasons for clinical failure. To address this, composite membranes of polycaprolactone (PCL) and gelatin (Gel) loaded with zinc oxide nanoparticles (ZnO-NPs; 1, 3 and 6 wt% relative to PCL content) were fabricated by electrospinning. To fabricate homogeneous fibrillar membranes, acetic acid was used as a sole common solvent to enhance the miscibility of PCL and Gel in the electrospinning solutions. The effects of ZnO-NPs in the physico-chemical, mechanical and in vitro biological properties of composite membranes were studied. The composite membranes showed adequate mechanical properties to offer a satisfactory clinical manipulation and an excellent conformability to the defect site while their degradation rate seemed to be appropriate to allow successful regeneration of periodontal defects. The presence of ZnO-NPs in the composite membranes significantly decreased the planktonic and the biofilm growth of the Staphylococcus aureus over time. Finally, the viability of human osteoblasts and human gingival fibroblasts exposed to the composite membranes with 1 and 3 wt% of ZnO-NPs indicated that those membranes are not expected to negatively influence the ability of periodontal cells to repopulate the defect site during GTR treatments. The results here obtained suggest that composite membranes of PCL and Gel loaded with ZnO-NPs have the potential to be used as structurally stable GTR membranes with local antibacterial properties intended for enhancing clinical treatments.
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Regeneración Tisular Dirigida/métodos , Nanopartículas del Metal/química , Staphylococcus aureus/efectos de los fármacos , Ingeniería de Tejidos/métodos , Óxido de Zinc/química , Antibacterianos/farmacología , Supervivencia Celular , Fibroblastos/efectos de los fármacos , Gelatina/química , Encía/efectos de los fármacos , Encía/metabolismo , Humanos , Membranas Artificiales , Pruebas de Sensibilidad Microbiana , Nanotecnología/métodos , Osteoblastos/efectos de los fármacos , Poliésteres/química , Staphylococcus aureus/metabolismo , Resistencia a la Tracción , TermogravimetríaRESUMEN
This study aimed at investigating the synthesis, characterization, and search for a biotechnological application proposal for poly [(R)-3-hydroxybutyric acid] (PHB) grafted with the n-hydroxyethyl acrylamide (HEAA) monomer. The novel copolymer was prepared by 60Co gamma radiation-induced-graft polymerization. The effect of different solvents in the graft polymerization; the degree of grafting, crystallinity, and hydrophilicity; the morphology and the thermal properties were evaluated. The polyurethane fabricated from the grafted PHB was suggested as a scaffold. The enzymatic degradation behavior and the spectroscopic, morphological, mechanical, and biological properties of the composites were assessed. According to the results, the successful grafting of HEAA onto PHB was verified. The grafting was significantly affected by the type of solvent employed. A decreased crystallinity and increased hydrophilicity of the graft copolymer, concerning the PHB, was found. An increased roughness was observed in the morphology of the polymer after grafting. The thermodynamic parameters, except for the glass transition temperature, also decreased for the synthetic biopolymer. The intended use of these scaffolds for skin tissue engineering was supported by a proper degradability and degree of porosity, improved mechanical properties, the optimal culture of human fibroblasts, and its transfection with a plasmid vector containing an enhanced green fluorescent protein.
Asunto(s)
Poliuretanos , Ingeniería de Tejidos , Ácido 3-Hidroxibutírico , Acrilamida , Rayos gamma , Humanos , Hidroxibutiratos , Poliésteres , Prohibitinas , Andamios del TejidoRESUMEN
A nano-composite from biologically obtained chitin nanofillers homogenously dispersed in a poly(ε-caprolactone) matrix was successfully achieved by an ultrasonication-assisted non-toxic and non-aqueous methodology. For this purpose, biological chitin was obtained from lactic acid fermentation of shrimp wastes and converted into chitin whiskers by acidic hydrolysis in a novel process at low temperature (4°C) that enhanced the distribution and yield. Additionally, the polyester matrix was enzymatically produced in a non-toxic compressed fluid (1,1,1,2-tetrafluoroethane at 25bar and 65°C) medium. The homogeneous distribution of the nanofiller in the matrix was corroborated by confocal and atomic force microscopies. Films of the nanocomposite were physicochemically characterized to assess its adequate properties. Additionally, the qualitative viability of human fibroblasts and osteoblasts cells was studied on the produced nanocomposite films showing good biocompatibility.
Asunto(s)
Quitina/química , Nanocompuestos/química , Nanopartículas/química , Poliésteres/química , Adulto , Animales , Candida/enzimología , Niño , Quitina/aislamiento & purificación , Fibroblastos , Tecnología Química Verde , Humanos , Hidrocarburos Fluorados/química , Hidrólisis , Lactobacillus plantarum/química , Lipasa/química , Osteoblastos , Tamaño de la Partícula , Penaeidae/químicaRESUMEN
Chitosan, sodium alginate and gel of Aloe vera (Aloe barbadensis Miller) were employed for the preparation of polyelectrolyte complexes at pH 4 and 6. FT-IR spectroscopy analysis showed evidence on complexes formation and incorporation of the Aloe vera gel. The ζ potential determination of the polyelectrolyte complexes revealed the presence of surface charges in the range of -20 to -24â¯mV, which results in stable systems. The dynamic moduli exhibited a high dependence on angular frequency, which is commonly found in solutions of macromolecules. The materials showed human fibroblast and lymphocyte viabilities up to 90% in agreement with null cytotoxicity. The polyelectrolyte complexes at pH 6 with Ca2+ were stable, showed high water absorption, satisfactory morphology, pore size and rigidity, characteristics that allowed significant human fibroblast migration in wound closure in vitro assays.