The chief obstacle for reconstructing the bladder is the absence of a biomaterial, either permanent or biodegradable, that will function as a suitable scaffold for the natural process of regeneration. In this study, polylactic-co-glycolic acid (PLGA) plus collagen or fibrin was evaluated for its suitability as a scaffold for urinary bladder construct. Human adipose-derived stem cells (HADSCs) were cultured, followed by incubation in smooth muscle cells differentiation media. Differentiated HADSCs were then seeded onto PLGA mesh supported with collagen or fibrin. Evaluation of cell-seeded PLGA composite immersed in culture medium was performed under a light and scanning microscope. To determine if the composite is compatible with the urodynamic properties of urinary bladder, porosity and leaking test was performed. The PLGA samples were subjected to tensile testing was pulled until PLGA fibers break. The results showed that the PLGA composite is biocompatible to differentiated HADSCs. PLGA-collagen mesh appeared to be optimal as a cell carrier while the three-layered PLGA-fibrin composite is better in relation to its leaking/ porosity property. A biomechanical test was also performed for three-layered PLGA with biological adhesive and three-layered PLGA alone. The tensile stress at failure was 30.82 ± 3.80 (MPa) and 34.36 ± 2.57 (MPa), respectively. Maximum tensile strain at failure was 19.42 ± 2.24 (mm) and 23.06 ± 2.47 (mm), respectively. Young's modulus was 0.035 ± 0.0083 and 0.043 ± 0.012, respectively. The maximum load at break was 58.55 ± 7.90 (N) and 65.29 ± 4.89 (N), respectively. In conclusion, PLGA-Fibrin fulfils the criteria as a scaffold for urinary bladder reconstruction.
With the trend for green technology, the study focused on utilizing a forgotten herb to produce an eco-friendly coating. Andrographis paniculata or the kalmegh leaves extract (KLE) has been investigated for its abilities in retarding the corrosion process due to its excellent anti-oxidative and antimicrobial properties. Here, KLE was employed as a novel additive in coatings and formulations were made by varying its wt%: 0, 3, 6, 9, and 12. These were applied to stainless steel 316L immersed in seawater for up to 50 days. The samples were characterized and analyzed to measure effectiveness of inhibition of corrosion and microbial growth. The best concentration was revealed to be 6 wt% KLE; it exhibited the highest performance in improving the ionic resistance of the coating and reducing the growth of bacteria.
Active ingredients of ginsenoside, Rg1 and Re, are able to inhibit the proliferation of vascular smooth muscle cells and promote the growth of vascular endothelial cells. These capabilities are of interest for developing a novel drug-eluting stent to potentially solve the current problem of late-stent thrombosis and poor endotheliazation. Therefore, this study was aimed to incorporate ginsenoside into degradable coating of poly(lactic-co-glycolic acid) (PLGA). Drug mixture composed of ginseng extract and 10% to 50% of PLGA (xPLGA/g) was coated on electropolished stainless steel 316L substrate by using a dip coating technique. The coating was characterized principally by using attenuated total reflectance-Fourier transform infrared spectroscopy, scanning electron microscopy and contact angle analysis, while the drug release profile of ginsenosides Rg1 and Re was determined by using mass spectrometry at a one month immersion period. Full and homogenous coating coverage with acceptable wettability was found on the 30PLGA/g specimen. All specimens underwent initial burst release dependent on their composition. The 30PLGA/g and 50PLGA/g specimens demonstrated a controlled drug release profile having a combination of diffusion- and swelling-controlled mechanisms of PLGA. The study suggests that the 30PLGA/g coated specimen expresses an optimum composition which is seen as practicable for developing a controlled release drug-eluting stent.
The combination of metallic bio-inert material, stainless-steel 316L (SS316L) and a bio-active material, hydroxyapatite (HA) can produce a composite which has superior properties for orthopaedic applications. The main objective of this study is to investigate the effects of sintering temperature and holding time on the physical and mechanical properties of the sintered part. 50wt.% SS316L and 50wt.% HA were mixed with a binder system of palm stearin (PS) and polyethylene (PE) at 61 vol.% powder loading. Rheological properties show a pseudo-plastic behaviour of the feedstock, where viscosity decreases with increasing shear rate. The feedstock was injection moulded into a tensile bar shape while thermal debinding was carried out at 320°C and 500°C. The brown parts were sintered at 1000, 1100, 1200 and 1300°C, with three different sintering times of 1, 3 and 5 hours in the furnace. It was found that the highest sintered density measured was 95.61% of the theoretical density. In addition, the highest hardness and Young's modulus measured were 150.45 HV and 52.61 GPa respectively, which are higher than those of human bone. The lowest percentage of carbon content was 0.022wt.% given by the sample sintered at 1300°C for 1 hour. Therefore, SS316L/HA composite with good mechanical and physical properties was successfully produced through the PIM process.
Biofilms are a complex group of microbial cells that adhere to the exopolysaccharide matrix present on the surface of medical devices. Biofilm-associated infections in the medical devices pose a serious problem to the public health and adversely affect the function of the device. Medical implants used in oral and orthopedic surgery are fabricated using alloys such as stainless steel and titanium. The biological behavior, such as osseointegration and its antibacterial activity, essentially depends on both the chemical composition and the morphology of the surface of the device. Surface treatment of medical implants by various physical and chemical techniques are attempted in order to improve their surface properties so as to facilitate bio-integration and prevent bacterial adhesion. The potential source of infection of the surrounding tissue and antimicrobial strategies are from bacteria adherent to or in a biofilm on the implant which should prevent both biofilm formation and tissue colonization. This article provides an overview of bacterial biofilm formation and methods adopted for the inhibition of bacterial adhesion on medical implants.
STUDY OBJECTIVE: To assess the morphologic features of anterior armed transobturator collagen-coated polypropylene mesh and its clinical outcomes in pelvic reconstructive surgery to treat pelvic organ prolapse.
DESIGN: Evidence obtained from several timed series with intervention (Canadian Task Force classification II-3).
SETTING: Chang Gung Memorial Hospital, Taoyuan, Taiwan, China.
PATIENTS: Between April 2010 and October 2012, 70 patients underwent surgery to treat symptomatic pelvic organ prolapse, stage III/IV according to the POP-Q (Pelvic Organ Quantification System).
INTERVENTION: Anterior armed transobturator collagen-coated mesh.
MEASUREMENT AND MAIN RESULTS: Morphologic findings and clinical outcome were measured. Morphologic features were assessed via 2-dimensional introital ultrasonography and Doppler studies. Clinical outcome was measured via subjective and objective outcome. Objective outcome was assessed via the 9-point site-specific staging method of the International Continence Society Pelvic Organ Prolapse Quantification before the operation and at 1-year postoperative follow-up. Subjective outcome was based on 4 validated questionnaires: the 6-item UDI-6 (Urogenital Distress Inventory), the 7-item IIQ-7 (Incontinence Impact Questionnaire), the 6-item POPDI-6 (Pelvic Organ Prolapse Distress Inventory 6), and the 12-item PISQ-12 (Pelvic Organ Prolapse/Urinary Incontinence Sexual Questionnaire), at baseline and at 12 months after the operation. Data were obtained for 65 patients who underwent the combined surgery and were able to comply with follow-up for >1 year. Ultrasound studies reveal that mesh length tends to shorten and decrease in thickness over the 1-year follow-up. Vagina thickness also was reduced. Neovascularization through the mesh was observed in <8.5% of patients in the first month and at 1 year, and was evident in approximately 83%. The mesh exposure rate was 6.4%. The recorded objective cure was 90.8% (59 of 65 patients), and subjective cure was 89.2% (58 of 65 patients) at mean (SD) follow-up of 19.40 (10.98) months. At 2 years, UDI-6, IIQ-7, and POPDI-6 scores were all significantly decreased (p < .001), whereas the PISQ-12 score was significantly increased (p = .01).
CONCLUSIONS: Ultrasound features suggest that the degeneration of collagen barrier may be longer than expected and that integration of collagen-coated mesh could occur up to 1 year. A substantially good clinical outcome was noted.
KEYWORDS: Anterior vaginal mesh; Collagen-coated mesh; Morphology; Outcome; Pelvic organ prolapse
The addition of a photocatalyst to ordinary building materials such as concrete creates environmentally friendly materials by which air pollution or pollution of the surface can be diminished. The use of LiNbO3 photocatalyst in concrete material would be more beneficial since it can produce artificial photosynthesis in concrete. In these research photoassisted solid-gas phases reduction of carbon dioxide (artificial photosynthesis) was performed using a photocatalyst, LiNbO3, coated on concrete surface under illumination of UV-visible or sunlight and showed that LiNbO3 achieved high conversion of CO2 into products despite the low levels of band-gap light available. The high reaction efficiency of LiNbO3 is explained by its strong remnant polarization (70 µC/cm(2)), allowing a longer lifetime of photoinduced carriers as well as an alternative reaction pathway. Due to the ease of usage and good photocatalytic efficiency, the research work done showed its potential application in pollution prevention.
Combination of bioactive material such as hydroxyapatite (HAp) with antibacterial agents would have great potential to be used as bone implant materials to avert possible bacterial infection that can lead to implant-associated diseases. The present study aimed to develop an antibacterial silver nanoparticle-decorated hydroxyapatite (HAp/AgNPs) nanocomposite using chemical reduction and thermal calcination approaches. In this work, natural HAp that was extracted from chicken bone wastes is used as support matrix for the deposition of silver nanoparticles (AgNPs) to produce HAp/AgNPs nanocomposite. XRD, FESEM-EDX, HRTEM, and XPS analyses confirmed that spherical AgNPs were successfully synthesized and deposited on the surface of HAp particles, and the amount of AgNPs adhered on the HAp surface increased with increasing AgNO3 concentration used. The synthesized HAp/AgNPs nanocomposites demonstrated strong antibacterial activity against Staphylococcus aureus bacteria, where the antibacterial efficiency is relied on the amount and size of deposited AgNPs. In addition, the in vitro bioactivity examination in Hank's balanced salt solution showed that more apatite were grown on the surface of HAp/AgNPs nanocomposite when AgNO3 concentration used >1 wt.%. Such nanocomposite with enhanced bioactivity and antibacterial properties emerged as a promising biomaterial to be applied for dentistry and orthopedic implantology.
This study was aimed to improve of the corrosion resistance and mechanical properties of Mg/15TiO2/5HA nanocomposite by silicon and magnesium oxide coatings prepared using a powder metallurgy method. The phase evolution, chemical composition, microstructure and mechanical properties of uncoated and coated samples were characterized. Electrochemical and immersion tests used to investigate the in vitro corrosion behavior of the fabricated samples. The adhesion strength of ~36MPa for MgO and ~32MPa for Si/MgO coatings to substrate was measured by adhesion test. Fabrication a homogenous double layer coating with uniform thicknesses consisting micro-sized particles of Si as outer layer and flake-like particles of MgO as the inner layer on the surface of Mg/15TiO2/5HA nanocomposite caused the corrosion resistance and ductility increased whereas the ultimate compressive stress decreased. However, after immersion in SBF solution, Si/MgO-coated sample indicates the best mechanical properties compared to those of the uncoated and MgO-coated samples. The increase of cell viability percentage of the normal human osteoblast (NHOst) cells indicates the improvement in biocompatibility of Mg/15TiO2/5HA nanocomposite by Si/MgO coating.
Tissue engineering scaffolds with oxygen generating elements have shown to be able to increase the level of oxygen and cell survivability in specific conditions. In this study, biphasic calcium phosphate (BCP) scaffolds with the composition of 60% hydroxyapatite (HA) and 40% beta-tricalcium phosphate (β-TCP), which have shown a great potential for bone tissue engineering applications, were fabricated by a direct-write assembly (robocasting) technique. Then, the three-dimensional (3D)-printed scaffolds were coated with different ratios of an oxygen releasing agent, calcium peroxide (CPO), which encapsulated within a polycaprolactone (PCL) matrix through dip-coating, and used for in situ production of oxygen in the implanted sites. The structure, composition and morphology of the prepared scaffolds were characterized by different techniques. The oxygen release kinetics and biological investigations of the scaffolds were also studied in vitro. The results showed that oxygen release behaviour was sustained and dependant on the concentration of CPO encapsulated in the PCL coating matrix. It was also demonstrated that the coated scaffolds, having 3% CPO in the coating system, could provide a great potential for promoting bone ingrowth with improving osteoblast cells viability and proliferation under hypoxic conditions. The findings indicated that the prepared scaffolds could play a significant role in engineering of large bone tissue implants with limitations in oxygen diffusion.