The Incorporation of Etanercept into a Porous Tri-Layer Scaffold for Restoring and Repairing Cartilage Tissue.

Cartilage diseases currently affect a high percentage of the world's population. Almost all of these diseases, such as osteoarthritis (OA), cause inflammation of this soft tissue. However, this could be controlled with biomaterials that act as an anti-inflammatory delivery system, capable of dosing these drugs over time in a specific area. The objective of this study was to incorporate etanercept (ETA) into porous three-layer scaffolds to decrease the inflammatory process in this soft tissue. ETA is a blocker of pro-inflammatory cytokines, such as tumour necrosis factor alpha (TNF-α) and interleukin 6 (IL-6). For this reason, the scaffold was built based on natural polymers, including chitosan and type I collagen. The scaffold was grafted next to subchondral bone using hydroxyapatite as filler. One of the biomaterials obtained was also crosslinked to compare its mechanical properties with the non-treated one. Both samples' physicochemical properties were studied with SEM, micro-CT and photoacoustic imaging, and their rheological properties were also compared. The cell viability and proliferation of the human chondrocyte C28/I2 cell line were studied in vitro. An in vitro and in vivo controlled release study was evaluated in both specimens. The ETA anti-inflammatory effect was also studied by in vitro TNF-α and IL-6 production. The crosslinked and non-treated scaffolds had rheological properties suitable for this application. They were non-cytotoxic and favoured the in vitro growth of chondrocytes. The in vitro and in vivo ETA release showed desirable results for a drug delivery system. The TNF-α and IL-6 production assay showed that this drug was effective as an anti-inflammatory agent. In an in vivo OA mice model, safranin-O and fast green staining was carried out. The OA cartilage tissue improved when the scaffold with ETA was grafted in the damaged area. These results demonstrate that this type of biomaterial has high potential for clinical applications in tissue engineering and as a controlled drug delivery system in OA articular cartilage.

The Effects of Crosslinking on the Rheology and Cellular Behavior of Polymer-Based 3D-Multilayered Scaffolds for Restoring Articular Cartilage.

Polymer-based tri-layered (bone, intermediate and top layers) scaffolds used for the restoration of articular cartilage were prepared and characterized in this study to emulate the concentration gradient of cartilage. The scaffolds were physically or chemically crosslinked. In order to obtain adequate scaffolds for the intended application, the impact of the type of calcium phosphate used in the bone layer, the polymer used in the intermediate layer and the interlayer crosslinking process were analyzed. The correlation among SEM micrographs, physical-chemical characterization, swelling behavior, rheological measurements and cell studies were examined. Storage moduli at 1 Hz were 0.3-1.7 kPa for physically crosslinked scaffolds, and 4-5 kPa (EDC/NHS system) and 15-20 kPa (glutaraldehyde) for chemically crosslinked scaffolds. Intrinsic viscoelasticity and poroelasticity were considered in discussing the physical mechanism dominating in different time/frequency scales. Cell evaluation showed that all samples are available as alternatives to repair and/or substitute cartilage in articular osteoarthritis.

Doxorubicin Loaded Poloxamer Thermosensitive Hydrogels: Chemical, Pharmacological and Biological Evaluation.

(1) Background: doxorubicin is a potent chemotherapeutic agent, but it has limitations regarding its side effects and therapy resistance. Hydrogels potentially deal with these problems, but several characterizations need to be optimized to better understand how hydrogel assisted chemotherapy works. Poloxamer 407 (P407) hydrogels were mixed with doxorubicin and physico-chemical, biological, and pharmacological characterizations were considered. (2) Methods: hydrogels were prepared by mixing P407 in PBS at 4 °C. Doxorubicin was added upon solutions became clear. Time-to-gelation, hydrogel morphology, and micelles were studied first. The effects of P407-doxorubicin were evaluated on MC-38 colon cancer cells. Furthermore, doxorubicin release was assessed and contrasted with non-invasive in vivo whole body fluorescence imaging. (3) Results: 25% P407 had favorable gelation properties with pore sizes of 30-180 µm. P407 micelles were approximately 5 nm in size. Doxorubicin was fully released in vitro from 25% P407 hydrogel within 120 h. Furthermore, P407 micelles strongly enhanced the anti-neoplastic effects of doxorubicin on MC-38 cells. In vivo fluorescence imaging revealed that hydrogels retained fluorescence signals at the injection site for 168 h. (4) Conclusions: non-invasive imaging showed how P407 gels retained drug at the injection site. Doxorubicin P407 micelles strongly enhanced the anti-tumor effects.

Thermosensitive hydrogels as sustained drug delivery system for CTLA-4 checkpoint blocking antibodies.

Thermosensitive poloxamer 407 (P407) hydrogels were evaluated as slow release system for optimizing CTLA-4 therapy. Slow release reduces systemic antibody levels and potentially mitigates the side effects of CTLA-4 therapy. The 25% P407 hydrogel is injectable at room temperature and depots are established quickly after subcutaneous injection. Scanning electron microscopy revealed the porous structure of the hydrogel, average pore surface was 1335 µm2. Release studies were optimized using the human IgG antibody. IgG was easily incorporated in the hydrogel by simple mixing and no antibodies were lost during preparation. In vitro, hydrogels showed low burst release within the first 24 h. Total IgG load was gradually released within 120 h. In vitro cytotoxicity assays showed that P407 is not cytotoxic and induces no immune activation by itself. In vivo, P407 hydrogels significantly reduced serum IgG levels, were biocompatible and were broken down 1 week after injection. Finally, local hydrogel delivery of anti-CTLA-4 antibodies near established tumors effectively slowed down tumor growth, whilst significantly reduced serum anti-CTLA-4 levels. Altogether, P407 hydrogels represent promising delivery systems for the optimization of CTLA-4 blocking therapy.

Design, construction, and biological testing of an implantable porous trilayer scaffold for repairing osteoarthritic cartilage.

Various tissue engineering systems for cartilage repair have been designed and tested over the past two decades, leading to the development of many promising cartilage grafts. However, no one has yet succeeded in devising an optimal system to restore damaged articular cartilage. Here, the design, assembly, and biological testing of a porous, chitosan/collagen-based scaffold as an implant to repair damaged articular cartilage is reported. Its gradient composition and trilayer structure mimic variations in natural cartilage tissue. One of its layers includes hydroxyapatite, a bioactive component that facilitates the integration of growing tissue on local bone in the target area after scaffold implantation. The scaffold was evaluated for surface morphology; rheological performance (storage, loss, complex, and time-relaxation moduli at 1 kHz); physiological stability; in vitro activity and cytotoxicity (on a human chondrocyte C28 cell line); and in vivo performance (tissue growth and biodegradability), in a murine model of osteoarthritis. The scaffold was shown to be mechanically resistant and noncytotoxic, favored tissue growth in vivo, and remained stable for 35 days postimplantation in mice. These encouraging results highlight the potential of this porous chitosan/collagen scaffold for clinical applications in cartilage tissue engineering.

Tissue Engineering: An Alternative to Repair Cartilage.

Herein we review the state-of-the-art in tissue engineering for repair of articular cartilage. First, we describe the molecular, cellular, and histologic structure and function of endogenous cartilage, focusing on chondrocytes, collagens, extracellular matrix, and proteoglycans. We then explore in vitro cell culture on scaffolds, discussing the difficulties involved in maintaining or obtaining a chondrocytic phenotype. Next, we discuss the diverse compounds and designs used for these scaffolds, including natural and synthetic biomaterials and porous, fibrous, and multilayer architectures. We then report on the mechanical properties of different cell-loaded scaffolds, and the success of these scaffolds following in vivo implantation in small animals, in terms of generating tissue that structurally and functionally resembles native tissue. Last, we highlight future trends in this field. We conclude that despite major technical advances made over the past 15 years, and continually improving results in cartilage repair experiments in animals, the development of clinically useful implants for regeneration of articular cartilage remains a challenge

Modificación de conocimientos sobre salud bucal en adolescentes de la Secundaria Básica "Orlando Fernández Badell" / Modification to knowledge on oral health in adolescents from "Orlando Fernández Badell" high school

Se realizó una intervención educativa en 40 estudiantes de la Secundaria Básica "Orlando Fernández Badell" de Santiago de Cuba -- seleccionados por muestro aleatorio simple --, de enero a julio del 2014, a fin de modificar sus conocimientos sobre salud bucal. En los adolescentes se efectuó un examen bucal y se aplicó un cuestionario, antes y después de presentar el programa de actividades educativas, que garantizó la motivación y el incremento significativo de los conocimientos sobre los aspectos abordados (95,0 %). En el estudio se obtuvo que la mayoría de los jóvenes desconocían información necesaria acerca de la higiene bucal y la dieta cariogénica; de modo que la actividad educativa desarrollada fue oportuna y efectiva, pues aportó excelentes resultados en la transformación de los conocimientos sobre salud bucal.

An educational intervention in 40 students from "Orlando Fernández Badell" high-school in Santiago de Cuba -- selected through single random sampling --, from January to July, 2014 was carried out in order to modify their knowledge on oral health. In the adolescents an oral examination was made and a questionnaire was applied, before and after presenting the program of educational activities which guaranteed the motivation and the significant increment of the knowledge on the aspects under study (95.0%). In the study it was obtained that most of the students ignored necessary information related to the oral hygiene and the cariogenic diet; so the developed educational activity was opportune and effective, because it provided excellent results in the transformation of the knowledge on oral health.

Modificación de conocimientos sobre salud bucal en adolescentes de la Secundaria Básica Orlando Fernández Badell / Modification to knowledge on oral health in adolescents from Orlando Fernández Badell high school

Se realizó una intervención educativa en 40 estudiantes de la Secundaria Básica Orlando Fernández Badell de Santiago de Cuba seleccionados por muestro aleatorio simple , de enero a julio del 2014, a fin de modificar sus conocimientos sobre salud bucal. En los adolescentes se efectuó un examen bucal y se aplicó un cuestionario, antes y después de presentar el programa de actividades educativas, que garantizó la motivación y el incremento significativo de los conocimientos sobre los aspectos abordados (95,0 por ciento). En el estudio se obtuvo que la mayoría de los jóvenes desconocían información necesaria acerca de la higiene bucal y la dieta cariogénica; de modo que la actividad educativa desarrollada fue oportuna y efectiva, pues aportó excelentes resultados en la transformación de los conocimientos sobre salud bucal(AU)

An educational intervention in 40 students from Orlando Fernández Badell high-school in Santiago de Cuba selected through single random sampling , from January to July, 2014 was carried out in order to modify their knowledge on oral health. In the adolescents an oral examination was made and a questionnaire was applied, before and after presenting the program of educational activities which guaranteed the motivation and the significant increment of the knowledge on the aspects under study (95.0 percent). In the study it was obtained that most of the students ignored necessary information related to the oral hygiene and the cariogenic diet; so the developed educational activity was opportune and effective, because it provided excellent results in the transformation of the knowledge on oral health(AU)

Algunas consideraciones sobre el surgimiento y la evolución de la medicina natural y tradicional / Some considerations on the emergence and history of natural and traditional medicine

La medicina natural, o naturismo, es un método curativo que utiliza múltiples medios naturales para permitir que el individuo adquiera un nivel máximo de salud. El sistema naturalista para curar enfermedades se basa en el uso de los recursos del medio ambiente para regular la dieta, la respiración, el ejercicio y los baños, y además saber emplear las fuerzas que eliminan todos los productos nocivos que se acumulan en el organismo, de manera que sea recuperada la vitalidad y se alcance un nivel de salud adecuado. A través de este trabajo se puede constatar que a medida que el hombre ha ido evolucionando, se han desarrollado las diferentes ramas de la medicina natural y tradicional(AU)

The natural medicine, or naturism, is a healing method which uses multiple natural means to allow the individual to acquire a maximum health level. The naturalistic system to cure diseases is based on the use of the resources of the environment to regulate diet, breathing, exercise and baths, and also to know how to use the forces eliminating all the noxious products which accumulate in the organism, so that the vitality is recovered and an appropriate health level is reached. Through this work it can verify that as man has evolved, the different branches of the natural and traditional medicine have been developed(AU)

Preparation and characterization of hydrophilic composites AA/EPMA loaded with hydroxyapatite.

Copolymeric composites of acrylamide (AA) and 2,3-epoxypropyl methacrylate (EPMA) with hydroxyapatite (HA) load were studied. Swelling studies reports an anomalous or non-Fickian behavior following a good fitting to a pseudo second order mathematical treatment (α = 0.05, p < 0.0001). The composites showed a strong dependence on pH, related with the variations in the swelling behavior. The addition of load induces a diminution of swelling capacity and an increase of diametric tensile strength (DTS) ranging between 20 and 90 kPa. The calorimetric experiments showed two steps at 78°C and 255°C assigned to water loss and samples Tg. The drug control released was adjusted to a two-term equation obtaining a diffusion coefficient around 10(-5) cm(2) /s. The samples showed a significant bioactivity in vitro and it was certified by SEM, EDS and surface area calculus.