Functional capacity, lung function, and muscle strength in patients undergoing hematopoietic stem cell transplantation: A prospective cohort study.

OBJECTIVE/BACKGROUND: Hematopoietic stem cell transplantation (HSCT) is a treatment for benign and malignant hematological diseases. These aggressive treatments cause reduced levels of physical activity, decreased lung function, and worse quality of life. Alterations in pulmonary function tests before HSCT are associated with the risk of respiratory failure and early mortality. The objective of this study was to evaluate functional capacity and lung function before and after HSCT and identify the predictors of mortality after 2 years. METHODS: A prospective cohort study was carried out with individuals with oncohematological diseases. The evaluations were carried out in two moments during hospitalization and at hospital discharge. Follow-up was carried out after 48 months. Assessments were carried out on 34 adults, using spirometry, manovacuometry, 6-Minute Walk Test (6MWT), Handgrip Strength Test, and 30-Second Chair Stand Test (30-s CST). RESULTS: There was a statistically significant reduction for the variables in forced vital capacity, forced expiratory volume predicted in the 1st second, Tiffeneau index, handgrip strength, and distance covered (% predicted) on the 6MWT (p < .05). There was a significant difference in the 30-s CST when individuals were compared according to the type of transplant. We found that a 10% reduction in the values of maximum inspiratory pressure (MIP) can predict an increased risk for mortality. CONCLUSIONS: Individuals undergoing HSCT have reduced functional capacity, lung function, and muscle strength during the hospitalization phase. Reduction in the values of MIP increases the risk of nonrelapse mortality.

Mechanical behavior of ropes based on polypropylene (PP) and poly(ethylene terephthalate) (PET) multifilament yarns for Achilles tendon partial substitution.

In some clinical cases, attending to the type and extension of the Achilles tendon injury, a partial replacement of the tissue may be needed. Driven by this, the authors developed different structures based on polypropylene (PP) or poly (ethylene terephthalate) (PET) multifilament yarns, using a textile technology-based technique, in order to mimic the fibrous structure of tendons. Those structures are based on a core/shell system, being the core composed by several sub-components (braids) and the shell based on braided yarns enclosing the core. It was observed that the load at failure of ropes is mainly defined by the number of yarns that compose it, but the strain level is mostly influenced by the production take-up rate of the core braids and consequently by the braid angle. The ropes stiffness level results from a combination of the yarns number and braid angle of the core braids. The structure based on PET yarns revealed a non-linear force-strain curve similar to a typical curve of a natural Achilles tendon (AT), presenting a load at failure, strain to failure and stiffness levels very promising for AT replacement. Moreover, the PET rope also revealed a very promising fatigue and appropriate creep resistance for the final application, being in accordance with what has been reported for native AT.

Novel cerium doped glass-reinforced hydroxyapatite with antibacterial and osteoconductive properties for bone tissue regeneration.

The aim of this work was to develop a bioactive bone substitute with an effective antibacterial ability based on a cerium (Ce) doped glass-reinforced hydroxyapatite (GR-HA) composite. Developed composites were physicochemically characterized, using x-ray diffraction (XRD) analysis, SEM, energy dispersive x-ray spectroscopy (EDS), and flexural bending strength (FBS) tests. X-ray photoelectron spectroscopy (XPS) analysis was performed to analyze the oxidation state of Ce in the prepared doped glass. The antimicrobial activity of the composites was evaluated against Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa; whether the cytocompatibility profile was assayed with human osteoblastic-like cells (Mg-63 cell line). The results revealed that the Ce inclusion in the GR-HA matrix induced the antimicrobial ability of the composite. In addition, Ce-doped materials reported an adequate biological behavior following seeding of osteoblastic populations, by inducing cell adhesion and proliferation. Developed materials were also found to enhance the expression of osteoblastic-related genes. Overall, the developed GR-HA_Ce composite is a prospective candidate to be used within the clinical scenario with a successful performance due to the effective antibacterial properties and capability of enhancing the osteoblastic cell response.

Current Approaches and Future Trends to Promote Tendon Repair.

Tendons are composed by extracellular collagen fibres arranged in regular arrays and are responsible to transmit tensile forces from a muscle to a bone. Due to their poor healing ability, in some cases tendons injuries are debilitating impairments that affect life quality among adult population worldwide. In the last years, attending to the social and economic concern associated to the high prevalence of tendons injuries and the limited success of the available current treatments, several scaffolds have been developed. Some of these scaffolds are intended to be used as graft-augmentation devices and others to fully replace a damaged tendon. The synthetic ones present superior mechanical characteristics compared to biological scaffolds. However, attending to the specific tendons physiology, even the synthetic scaffolds still don´t present the ideal mechanical properties to accomplish a complete and long-term functional tissue repair. Therefore, to enhance tendogenesis when using a tendon engineering approach, several methodologies have been developed to associate with scaffolds, including surface modification and cell seeding.

Biological evaluation of alginate-based hydrogels, with antimicrobial features by Ce(III) incorporation, as vehicles for a bone substitute.

A novel hydrogel, based on an alginate/hyaluronate mixture and Ce(III) ions, with effective bioactive and antimicrobial ability was developed to be used as vehicle of a synthetic bone substitute producing an injectable substitute (IBS). Firstly, three different IBSs were prepared using three developed alginate-based hydrogels, the hydrogel Alg composed by alginate, the hydrogel Alg/Ch composed by an alginate/chitosan mixture and the hydrogel Alg/HA composed by an alginate/hyaluronate mixture. MG63 cells viability on the IBSs was evaluated, being observed a significantly higher cell viability on the Alg/HA_IBS at all time points, which indicates a better cell adaptation to the material, increasing their predisposition to produce extracellular matrix and thus allowing a better bone regeneration. Moreover, SEM analysis showed evident filopodia and a spreader shape of MG63 cells when seeded on Alg/HA_IBS. This way, based upon the in vitro results, the hydrogel Alg/HA was chosen to the in vivo study by subcutaneous implantation in an animal model, promoting a slight irritating tissue response and visible tissue repairing. The next step was to grant antimicrobial properties to the hydrogel that showed the best biological behavior by incorporation of Ce(III) ions into the Alg/HA, producing the hydrogel Alg/HA2. The antimicrobial activity of these hyaluronate-based hydrogels was evaluated against Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa and Candida albicans. Results showed that Ce(III) ions can significantly enhance the hydrogel antimicrobial ability without compromising the osteoconductivity improvement promoted by the vehicle association to the synthetic bone substitute.

Development and characterization of novel alginate-based hydrogels as vehicles for bone substitutes.

In this work three different hydrogels were developed to associate, as vehicles, with the synthetic bone substitute GR-HAP. One based on an alginate matrix (Alg); a second on a mixture of alginate and chitosan (Alg/Ch); and a third on alginate and hyaluronate (Alg/HA), using Ca(2+) ions as cross-linking agents. The hydrogels, as well as the respective injectable bone substitutes (IBSs), were fully characterized from the physical-chemical point of view. Weight change studies proved that all hydrogels were able to swell and degrade within 72 h at pH 7.4 and 4.0, being Alg/HA the hydrogel with the highest degradation rate (80%). Rheology studies demonstrated that all hydrogels are non-Newtonian viscoelastic fluids, and injectability tests showed that IBSs presented low maximum extrusion forces, as well as quite stable average forces. In conclusion, the studied hydrogels present the necessary features to be successfully used as vehicles of GR-HAP, particularly the hydrogel Alg/HA.