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Abstract The present study investigates the effect of an oxidized nanocrystalline diamond (O-NCD) coating functionalized with bone morphogenetic protein 7 (BMP-7) on human osteoblast maturation and extracellular matrix mineralization in vitro and on new bone formation in vivo. The chemical structure and the morphology of the NCD coating and the adhesion, thickness and morphology of the superimposed BMP-7 layer have also been assessed. The material analysis proved synthesis of a conformal diamond coating with a fine nanostructured morphology on the Ti6Al4V samples. The homogeneous nanostructured layer of BMP-7 on the NCD coating created by a physisorption method was confirmed by AFM. The osteogenic maturation of hFOB 1.19 cells in vitro was only slightly enhanced by the O-NCD coating alone without any increase in the mineralization of the matrix. Functionalization of the coating with BMP-7 resulted in more pronounced cell osteogenic maturation and increased extracellular matrix mineralization. Similar results were obtained in vivo from micro-CT and histological analyses of rabbit distal femurs with screws implanted for 4 or 12 weeks. While the O-NCD-coated implants alone promoted greater thickness of newly-formed bone in direct contact with the implant surface than the bare material, a further increase was induced by BMP-7. It can be therefore concluded that O-NCD coating functionalized with BMP-7 is a promising surface modification of metallic bone implants in order to improve their osseointegration.

Addition of perfluorodecalin with gas-transporting function to the liquid medium during submerged cultivation of actinomycetes of the genus Streptomyces resulted in higher intensity and level of the biomass synthesis and increased production of streptomycin and daunorubicin. Addition of perfluorodecalin to the medium provided a 2.0-2.3-fold surpass of the maximum antibiotic production (achieved by the 120th-144th hours of the culture growth) vs. the antibiotic accumulation peaks in the control.

Chronic wounds represent a significant socio-economic problem, and the improvement of their healing is therefore an essential issue. This paper describes the preparation and biological properties of a novel functionalized nanofiber wound dressing consisting of a polycaprolactone nanofiber carrier modified by a drug delivery system, based on the lipid particles formed by 1-tetradecanol and encapsulated gentamicin and tocopherol acetate. The cytotoxicity of extracts was tested using a metabolic activity assay, and the antibacterial properties of the extracts were tested in vitro on the bacterial strains Staphylococcus aureus and Pseudomonas aeruginosa. The effect of the wound dressing on chronic wound healing was subsequently tested using a mouse model. Fourteen days after surgery, the groups treated by the examined wound cover showed a lower granulation, reepithelization, and inflammation score compared to both the uninfected groups, a lower dermis organization compared to the control, a higher scar thickness compared to the other groups, and a higher thickness of hypodermis and bacteria score compared to both the uninfected groups. This work demonstrates the basic parameters of the safety (biocompatibility) and performance (effect on healing) of the dressing as a medical device and indicates the feasibility of the concept of its preparation in outpatient conditions using a suitable functionalization device.

Hydrogels are suitable for osteochondral defect regeneration as they mimic the viscoelastic environment of cartilage. However, their biomechanical properties are not sufficient to withstand high mechanical forces. Therefore, we have prepared electrospun poly-ε-caprolactone-chitosan (PCL-chit) and poly(ethylene oxide)-chitosan (PEO-chit) nanofibers, and FTIR analysis confirmed successful blending of chitosan with other polymers. The biocompatibility of PCL-chit and PEO-chit scaffolds was tested; fibrochondrocytes and chondrocytes seeded on PCL-chit showed superior metabolic activity. The PCL-chit nanofibers were cryogenically grinded into microparticles (mean size of about 500 µm) and further modified by polyethylene glycol–biotin in order to bind the anti-CD44 antibody, a glycoprotein interacting with hyaluronic acid (PCL-chit-PEGb-antiCD44). The PCL-chit or PCL-chit-PEGb-antiCD44 microparticles were mixed with a composite gel (collagen/fibrin/platelet rich plasma) to improve its biomechanical properties. The storage modulus was higher in the composite gel with microparticles compared to fibrin. The Eloss of the composite gel and fibrin was higher than that of the composite gel with microparticles. The composite gel either with or without microparticles was further tested in vivo in a model of osteochondral defects in rabbits. PCL-chit-PEGb-antiCD44 significantly enhanced osteogenic regeneration, mainly by desmogenous ossification, but decreased chondrogenic differentiation in the defects. PCL-chit-PEGb showed a more homogeneous distribution of hyaline cartilage and enhanced hyaline cartilage differentiation.

Martin Plencner,1,2,* Barbora East,3,* Zbynek Tonar,4 Martin Otáhal,5 Eva Prosecká,1,2 Michala Rampichová,2,6 Tomáš Krejčí,3 Andrej Litvinec,2,7 Matej Buzgo,2,6 Andrea Míčková,1,2,6 Alois Nečas,8 Jirí Hoch,3 Evžen Amler1,2,9 1Institute of Biophysics, Second Faculty of Medicine, Charles University in Prague, Prague, 2Laboratory of Tissue Engineering, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Prague, 3Department of Surgery, Second Faculty of Medicine, Charles University in Prague, Prague, 4Biomedical Centre, Faculty of Medicine in Pilsen, Charles University in Prague, Pilsen, 5Department of Anatomy and Biomechanics, Faculty of Physical Education and Sport, Charles University in Prague, Prague, 6University Center for Energy Efficient Buildings, Czech Technical University in Prague, Buštehrad, 7Department of Breeding and Zoohygiene of Laboratory Animals, Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, 8Department of Surgery and Orthopedics, Small Animal Clinic, Faculty of Veterinary Medicine, University of Veterinary and Pharmaceutical Science Brno, Central European Institute of Technology, Brno, 9Faculty of Biomedical Engineering, Czech Technical University in Prague, Kladno, Czech Republic *These authors contributed equally to this work Abstract: Incisional hernia affects up to 20% of patients after abdominal surgery. Unlike other types of hernia, its prognosis is poor, and patients suffer from recurrence within 10 years of the operation. Currently used hernia-repair meshes do not guarantee success, but only extend the recurrence-free period by about 5 years. Most of them are nonresorbable, and these implants can lead to many complications that are in some cases life-threatening. Electrospun nanofibers of various polymers have been used as tissue scaffolds and have been explored extensively in the last decade, due to their low cost and good biocompatibility. Their architecture mimics the natural extracellular matrix. We tested a biodegradable polyester poly-Ԑ-caprolactone in the form of nanofibers as a scaffold for fascia healing in an abdominal closure-reinforcement model for prevention of incisional hernia formation. Both in vitro tests and an experiment on a rabbit model showed promising results. Keywords: nanofibers, growth factors, surgical mesh, hernia regeneration, in vivo

This study was carried out to investigate how pinworm infection in rats affects nutrient digestibility in the hosts. Twenty-four male outbred Wistar rats were randomly divided into two groups of 12 rats each. The rats from the first group (GI) were kept in cages with bedding containing pinworm eggs, and the second (control) group (GII) were kept in a separate room in clean, uncontaminated filter-top cages. The animals were put into individual metabolic cages later. Metabolic trials lasted five days and records of animal weight, food ingestion, and faecal weight were taken daily. Based on laboratory analysis of the feed and faecal nutrient content, digestibility values were determined. On day 15 of the experiment, the animals were euthanized. Although Syphacia muris were found in all rats from the GI group, animals exhibited no clinical signs. In our experiment, S. muris infection reduced the overall digestibility of all measured nutrients (P < 0.01). The most significant differences in digestibility were observed in the case of crude fibre and mineral matter (P < 0.01). [ABSTRACT FROM AUTHOR]