The Structural, Thermal and Morphological Characterization of Polylactic Acid/Β-Tricalcium Phosphate (PLA/Β-TCP) Composites upon Immersion in SBF: A Comprehensive Analysis.

Biocomposite films based on PLA reinforced with different ß-TCP contents (10%, 20%, and 25%wt.) were fabricated via solvent casting and immersed in SBF for 7, 14, and 21 days. The bioactivity, morphological, and thermal behavior of composites with immersion were studied using scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) microanalysis, weight loss (WL), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and gel permeation chromatography (GPC). This broad analysis leads to a deeper understanding of the evolution of the polymer-filler interaction with the degradation of the biocomposites. The results showed that ß-TCP gradually evolved into carbonated hydroxyapatite as the immersion time increased. This evolution affected the interaction of ß-TCP with PLA. PLA and ß-TCP interactions differed from PLA and carbonated hydroxyapatite interactions. It was observed that ß-TCP inhibited PLA hydrolysis but accelerated the thermal degradation of the polymer. ß-TCP retarded the cold crystallization of PLA and hindered its crystallinity. However, after immersion in SBF, particles accelerated the cold crystallization of PLA. Therefore, considering the evolution of ß-TCP with immersion in SBF is crucial for an accurate analysis of the biocomposites' degradation. These findings enhance the comprehension of the degradation mechanism in PLA/ß-TCP, which is valuable for predicting the degradation performance of PLA/ß-TCP in medical applications.

Real-world experience of vedolizumab use in Colombian patients with inflammatory bowel disease-EXVEDOCOL.

BACKGROUND: Real-world studies about the effectiveness and safety of vedolizumab (VDZ) in the treatment of inflammatory bowel disease (IBD) in Latin America are scarce. Our study describes the effectiveness and safety of VDZ in Colombian patients with IBD. METHODS: EXVEDOCOL (EXperience of VEDOlizumab in COLombia) was a retrospective, multicenter, observational study. Adults with IBD receiving a first dose of VDZ between July 2016 and October 2018 were included. The co-primary outcomes clinical response, and remission, were determined at week 14 and last visit during the maintenance phase (LVMP). The secondary outcomes, deep remission and loss of response were recorded at LVMP. RESULTS: Thirty-one patients (25 ulcerative colitis (UC), 6 Crohn's disease (CD)) were included. At week 14, clinical response was achieved by 87.1% (27/31) of the patients treated with VDZ, while loss of response was reported in 6.7% (2/30). The remission rate at week 14 was 65.5% (19/29) and 75.9% (22/29) at LVMP. Prior anti-TNF exposure was reported in 61.3% (19 patients) of whom 84.2% (16/19) achieved clinical response at week 14 and 89.5% (17/19) at LVMP. For anti-TNF naïve patients, clinical response was recorded in 91.7% (11/12) at week 14 and 100% (12/12) at LVMP. CONCLUSIONS: High clinical remission rates and safety profile highlight VDZ as a valuable treatment option for IBD patients. Anti-TNF naïve patients may derive greater benefit from therapy. Studies with larger cohorts could confirm these findings.

Metastable FeMg particles for controlling degradation rate, mechanical properties, and biocompatibility of Poly(l-lactic) acid (PLLA) for orthopedic applications.

Poly(l-lactic) acid (PLLA) is commonly used in bioabsorbable medical implants, but it suffers from slow degradation rate and rapid decline in mechanical properties for orthopedic applications. To address this drawback, recent research has explored the use of Mg as a filler for PLLA, resulting in composites with improved degradation rate and cytocompatibility compared to neat PLLA. In this study, FeMg powder particles were proposed as fillers for PLLA to investigate the potential of PLLA/FeMg composites for bioabsorbable implants. Cylinder specimens of PLLA, PLLA/Fe, PLLA/Mg and PLLA/FeMg were prepared using solvent casting followed by thermo-molding. The microstructure, thermal behavior, in vitro degradation behavior in simulated body fluid, mechanical properties and cytocompatibility of these composites were examined. The results indicate that the presence of FeMg particles prevents the deterioration of the composite mechanical properties, at least up to 14 days. Once a certain amount of degradation of the composite is reached, the degradation is faster than that of PLLA. Direct cytotoxicity assays revealed that pre-osteoblast MC3T3-E1 cells successfully adhered to and proliferated on the PLLA/FeMg surface. The inclusion of a low percentage of Mg into the Fe lattice not only accelerated the degradation rate of Fe but also improved its cytocompatibility. The enhanced degradation rate, mechanical properties, and osteoconductive properties of this composite make it a promising option for temporary orthopedic biomedical devices.

Bioabsorbable Composites Based on Polymeric Matrix (PLA and PCL) Reinforced with Magnesium (Mg) for Use in Bone Regeneration Therapy: Physicochemical Properties and Biological Evaluation.

Improvements in Tissue Engineering and Regenerative Medicine (TERM)-type technologies have allowed the development of specific materials that, together with a better understanding of bone tissue structure, have provided new pathways to obtain biomaterials for bone tissue regeneration. In this manuscript, bioabsorbable materials are presented as emerging materials in tissue engineering therapies related to bone lesions because of their ability to degrade in physiological environments while the regeneration process is completed. This comprehensive review aims to explore the studies, published since its inception (2010s) to the present, on bioabsorbable composite materials based on PLA and PCL polymeric matrix reinforced with Mg, which is also bioabsorbable and has recognized osteoinductive capacity. The research collected in the literature reveals studies based on different manufacturing and dispersion processes of the reinforcement as well as the physicochemical analysis and corresponding biological evaluation to know the osteoinductive capacity of the proposed PLA/Mg and PCL/Mg composites. In short, this review shows the potential of these composite materials and serves as a guide for those interested in bioabsorbable materials applied in bone tissue engineering.

Perforación gástrica por espina de pescado. Reporte de un caso y revisión de literatura / Gastric perforation caused by fish bone. Case report and literature review

Resumen La ingesta de cuerpos extraños es una entidad clínica común en el servicio de gastroenterología; la mayoría de veces estos pasan a través del tracto digestivo de manera espontánea y, en algunos casos, pueden presentar complicaciones como obstrucción o perforación. Es importante realizar un diagnóstico temprano con el fin de definir una terapia conservadora o quirúrgica inmediata. Se presenta el caso de una paciente de 67 años de edad que ingresó al servicio de urgencias por dolor abdominal de 16 días de evolución; como había sospecha de tumor gástrico sobreinfectado, se solicitó una endoscopia digestiva alta para la toma de biopsias, pero de forma sorpresiva se extrajo una espina de pescado de 3,5 cm sin complicaciones; posteriormente, se realizó el manejo del absceso gástrico con antibióticos por 14 días, con un buen desenlace clínico.

Abstract Foreign body ingestion is a common reason for consultation to the Gastroenterology Service. Most of these bodies pass through the digestive tract spontaneously and, in some cases, may cause complications such as obstruction or perforation. Early diagnosis is crucial to establish immediate conservative or surgical therapy. The following is the case of a 67-year-old patient admitted to the Emergency Department due to abdominal pain of 16 days of evolution. Since an over-infected gastric tumor was suspected, an upper gastrointestinal endoscopy was requested for biopsy. Strikingly, a 3.5cm fish bone was removed without complications. Gastric abscess was treated subsequently with antibiotics for 14 days, obtaining a good clinical outcome.

The Colombian Chemoprevention Trial: 20-Year Follow-Up of a Cohort of Patients With Gastric Precancerous Lesions.

BACKGROUND & AIMS: Helicobacter pylori eradication and endoscopic surveillance of gastric precancerous lesions are strategies to reduce gastric cancer (GC) risk. To our knowledge, this study is the longest prospective cohort of an H pylori eradication trial in a Hispanic population. METHODS: A total of 800 adults with precancerous lesions were randomized to anti-H pylori treatment or placebo. Gastric biopsy samples taken at baseline and 3, 6, 12, 16, and 20 years were assessed by our Correa histopathology score. A generalized linear mixed model with a participant-level random intercept was used to estimate the effect of H pylori status on the score over time. Logistic regression models were used to estimate progression by baseline diagnosis and to estimate GC risk by intestinal metaplasia (IM) subtype and anatomic location. RESULTS: Overall, 356 individuals completed 20 years of follow-up. Anti-H pylori therapy (intention-to-treat) reduced progression of the Correa score (odds ratio [OR], 0.59; 95% confidence interval [CI], 0.38-0.93). H pylori-negative status had a beneficial effect on the score over time (P = .036). Among individuals with IM (including indefinite for dysplasia) at baseline, incidence rates per 100 person-years were 1.09 (95% CI, 0.85-1.33) for low-grade/high-grade dysplasia and 0.14 (95% CI, 0.06-0.22) for GC. Incomplete-type (vs complete-type) IM at baseline presented higher GC risk (OR, 13.4; 95% CI, 1.8-103.8). Individuals with corpus (vs antrum-restricted) IM showed an OR of 2.1 (95% CI, 0.7-6.6) for GC. CONCLUSIONS: In a high-GC-risk Hispanic population, anti-H pylori therapy had a long-term beneficial effect against histologic progression. Incomplete IM is a strong predictor of GC risk.

In-vitro evaluation of Polylactic acid (PLA) manufactured by fused deposition modeling.

BACKGROUND: With additive manufacturing (AM) individual and biocompatible implants can be generated by using suitable materials. The aim of this study was to investigate the biological effects of polylactic acid (PLA) manufactured by Fused Deposition Modeling (FDM) on osteoblasts in vitro according to European Norm / International Organization for Standardization 10,993-5. METHOD: Human osteoblasts (hFOB 1.19) were seeded onto PLA samples produced by FDM and investigated for cell viability by fluorescence staining after 24 h. Cell proliferation was measured after 1, 3, 7 and 10 days by cell-counting and cell morphology was evaluated by scanning electron microscopy. For control, we used titanium samples and polystyrene (PS). RESULTS: Cell viability showed higher viability on PLA (95,3% ± 2.1%) than in control (91,7% ±2,7%). Cell proliferation was highest in the control group (polystyrene) and higher on PLA samples compared to the titanium samples. Scanning electron microscopy revealed homogenous covering of sample surface with regularly spread cells on PLA as well as on titanium. CONCLUSION: The manufacturing of PLA discs from polylactic acid using FDM was successful. The in vitro investigation with human fetal osteoblasts showed no cytotoxic effects. Furthermore, FDM does not seem to alter biocompatibility of PLA. Nonetheless osteoblasts showed reduced growth on PLA compared to the polystyrene control within the cell experiments. This could be attributed to surface roughness and possible release of residual monomers. Those influences could be investigated in further studies and thus lead to improvement in the additive manufacturing process. In addition, further research focused on the effect of PLA on bone growth should follow. In summary, PLA processed in Fused Deposition Modelling seems to be an attractive material and method for reconstructive surgery because of their biocompatibility and the possibility to produce individually shaped scaffolds.

Bioactivity of dexamethasone-releasing coatings on polymer/magnesium composites.

We developed biodegradable polymeric coatings loaded with increasing amounts of dexamethasone on composites based on polylactic acid and Mg particles for bone repair. Incorporation of Mg particles into the polymeric matrix improves the compressive behaviour of the polymer. Mg-containing composites release Mg2+ ions into the culture medium and improve mesenchymal stem cell (MSC) viability, enhance their osteogenic potential and promote the release of angiogenic factors. Dexamethasone-loaded coatings deposited on composites delay Mg2+ ion dissolution while releasing controlled amounts of the drug, which are highly dependent on initial payload. Release kinetic of dexamethasone from the coatings exhibits a fast initial release of the drug followed by a slower secondary release. Bioactivity of the released dexamethasone was explored by monitoring dose-dependent responses of MSCs and macrophages. Biological effects exerted by the released drug are similar to those observed in cells treated with solutions of the glucocorticoid, indicating that the method employed for inclusion of dexamethasone into the coatings does not impair its bioactive behaviour. Culturing MSCs on dexamethasone-releasing coatings enhances extracellular matrix production and initial induction to osteogenic commitment as a function of drug payload. Dexamethasone incorporated into the coatings presents anti-inflammatory activity, as shown by the decrease in the production of cytokines and angiogenic factors by macrophages and MSCs. Deposition of dexamethasone-releasing coatings on polymer/Mg composites appears to be a promising approach to delay composite degradation at the early stage of implantation and may be useful to attenuate inflammation and adverse foreign body reactions.

Incorporation of Mg particles into PDLLA regulates mesenchymal stem cell and macrophage responses.

In this work, we investigated a new approach to incorporate Mg particles within a PDLLA matrix using a solvent-free commercially available process. PDLLA/Mg composites were manufactured by injection moulding and the effects of Mg incorporated into PDLLA on MSC and macrophage responses were evaluated. Small amounts of Mg particles (≤ 1 wt %) do not cause thermal degradation of PDLLA, which retains its mechanical properties. PDLLA/Mg composites release hydrogen, alkaline products and Mg(2+) ions without changing pH of culture media. Mg-containing materials provide a noncytotoxic environment that enhances MSC viability. Concentration of Mg(2+) ions in extracts of MSCs increases with the increment of Mg content in the composites. Incorporation of Mg particles into PDLLA stimulates FN production, ALP activity, and VEGF secretion in MSCs, an effect mediated by degradation products dissolved from the composites. Degradation products of PDLLA induce an increase in MCP-1, RANTES, and MIP-1α secretion in macrophages while products of composites have minimal effect on these chemokines. Regulation of MSC behavior at the biomaterial's interface and macrophage-mediated inflammatory response to the degradation products is related to the incorporation of Mg in the composites. These findings suggest that including small amounts of Mg particles into polymeric devices can be a valuable strategy to promote osseointegration and reduce host inflammatory response.

Características del comportamiento suicida en cárceles de Colombia / Characteristics of suicide behavior in Colombian prisons / Características do comportamento suicida nas prisões da Colômbia

Objetivo. El estudio, de tipo descriptivo correlacional, buscó establecer cuáles de las variables de tiempo, modo y lugar, propias del contexto penitenciario y carcelario, aparecen con mayor frecuencia en 60 internos que se vieron involucrados con pensamientos de suicidio, intento de suicidio y suicidio consumado, en las cárceles y penitenciarías adscritas al Instituto Nacional Penitenciario y Carcelario de Colombia (INPEC), durante el primer trimestre del 2013. Método. La muestra intencional estuvo constituida por 60 internos, de los cuales el 68,3 % eran hombres y el 31,7 % mujeres, con una edad promedio de 28,02 años y una desviación estándar de 8,03 años. Resultados. A través de un formato de uso exclusivo del INPEC y mediante el software estadístico “Statisticals Package for the Social Sciences” (SPSS), se obtuvo que el intento de suicidio, con un 76,7 %, es la conducta que con mayor frecuencia se presenta. Asimismo, a través de la prueba de chi-cuadrado de Pearson (X2) se estableció la existencia de relaciones estadísticamente significativas entre el tipo de conducta suicida y el género, el género y el método utilizado, el lugar del acontecimiento y el tipo de conducta suicida. Conclusiones. La etapa inicial del encarcelamiento es el lapso de mayor riesgo (uno a cinco meses) en la aparición del intento suicida (41,7 %), lo que podría explicarse a partir del desajuste afectivo y emocional que fragmenta la vida habitual del interno, en cuanto a sus relaciones interpersonales e intrapersonales, donde hay ausencia de comunicación positiva, y se evidencia el estrés moral y la tensión psicológica (OMS, 2000).

Objective. This study of a descriptive correlational type was aimed at establishing which of the incarceration context variables of time, method and place appear more frequently in 60 inmates involved in situations dealing with suicidal thoughts, suicide attempts and completed suicide during the first quarter of 2013 in the prisons and correctional institutions attached to the INPEC, the National Penitentiary and Prison Institute of Colombia. Method. The intentional sample consisted of 60 inmates, 68.3 % of which were men and 31.7 % were women with an average age of 28.02 years and a standard deviation of 8.03 years. Results. Through a format for the exclusive use by the INPEC and the “Statisticals Package for the Social Sciences” (SPSS) software, the result obtained was that suicide attempt, with 76.7 %, is the most frequently occurring conduct. Likewise, through the Pearson Chi-squared test (X2), the existence of statistically significant relations between the suicidal behavior type and gender and method used was established, instead of event and type of suicidal conduct. Conclusions. The initial incarceration stage is the most risky period (one to five months) in the emergence of the first suicidal attempt (41.7 %), which may be explained as triggered by the affective and emotional maladjustment fragmenting the daily life of inmates in their interpersonal and intrapersonal relations, where positive communication is absent and both moral and psychological stress are revealed (OMS, 2000).

Objetivo. O estudo, do tipo descritivo correlacional, procurou estabelecer quais das variáveis do tempo, modo e lugar, próprias do contexto da prisão e penitenciário, aparecem mais frequentemente em 60 presos que estiveram envolvidos com pensamentos de suicídio, tentativa de suicídio e suicídio consumado, nas prisões e cadeias adscritas ao Instituto Nacional Penitenciário e de Prisões da Colômbia (INPEC), durante o primeiro trimestre de 2013. Método. A amostra intencional foi constituída por 60 presos, dos quais 68.3% eram homens e 31.7% mulheres, com uma idade média de 28.02 anos e um desvio padrão de 8.03 anos. Resultados. Através de um formato do uso exclusivo do INPEC e por meio do software estatístico “Statisticals Package for the Social Sciences” (SPSS), concluiu-se que a tentativa do suicídio, com un 76.7%, é a conduta que apresenta- se mais frequentemente. Também, através do teste do chi-quadrado de Pearson (X2) que estabeleceu a existência de relações estatisticamente significativas entre o tipo de conduta suicida e o gênero, o gênero e o método usado, o lugar do evento e o tipo de conduta suicida. Conclusões. A etapa inicial do aprisionamento é o lapso de maior risco (um a cinco meses) na aparição na tentativa suicida (41.7%), que poderia ser explicada a partir do desequilíbrio emocional e afetivo que fragmenta a vida habitual do preso, a respeito das suas relações interpessoais e intrapessoais, onde há uma ausência de comunicação positiva, e demonstra-se o stress moral e a tensão psicológica (OMS, 2000).

Colitis ulcerativa asociada con manifestaciones cutáneas / Ulcerative colitis asociated with cutaneous manifestations

El pioderma gangrenoso (PG) es una condición ulcerativa cutánea de causa desconocida descrita en el año 1930 por Brunsting, Goeckerman y O’Leary (1).La importancia de su diagnóstico radica en la asociación con enfermedades tales como la colitis ulcerosa (1, 2) (CU), la enfermedad de Crohn (3) (EC), artritis (4) y neoplasias hematológicas (5), además de su compromiso cutáneo que puede ser severo. Debido a su baja incidencia existen pocos antecedentes sobre el curso de esta enfermedad a largo plazo (6). Reportamos dos casos de pacientes con diagnóstico de pioderma gangrenoso como primera manifestación clínica de colitis ulcerativa; teniendo en cuenta que su asociación es baja y está entre el 1 y el 5 por ciento y donde las manifestaciones extraintestinales de la enfermedad inflamatoria (AU) intestinal pueden confundir al clínico (5)