Factor Affecting Geometry of TiO2 Nanotube Arrays (TNAs) in Aqueous and Organic Electrolyte

TiO2 nanotube arrays (TNA) have attracted scientific interest due to the combination of functional material properties with controllable nanostructure. Superior properties of TNA, including vectorial pathway of e− transport, minimized e− recombination, and high specific surface area render them as the most promising candidate for environment remediation, energy conversion and biocompatibility applications. The superior properties and efficacy of the TNA in various applications influenced by structural characteristics such as pore size, length and wall thickness. Therefore in this chapter the effect of various electrochemical parameters such as applied voltage, anodization time, electrolyte composition on the formation of controlled dimension of TNA in aqueous and organic electrolytes are reviewed

Localised Delivery of Cisplatin from Chitosan-Coated Titania Nanotube Array Nanosystems Targeting Nasopharyngeal Carcinoma

Pupose: Cisplatin (CDDP), while amongst the recognised chemotherapeutic drugs currently available, is known to have limitations; the lack of a single treatment approach and non-specific targeted therapies. Therefore, the development of an innovative strategy that could achieve localised CDDP treatment is an urgent undertaking. Recent advances in titania nanotube arrays (TNAs) technology have demonstrated promising applications for localised chemotherapeutic drug treatment. The present work investigated the efficiency of a TNA nanosystem for the localised CDDP treatment of nasopharyngeal carcinoma (NPC). Methods: Two models of the TNA nanosystem were prepared: CDDP loaded onto the TNA nanosystem surface (CDDP-TNA) and the other consisted of chitosan-coated CDDP-TNA. CDDP release from these two nanosystems was comprehensively tested on the NPC cells NPC/HK-1 and C666-1. The NPC cytotoxicity profile of the two CDDP-TNA nanosystems was evaluated after incubation for 24, 48 and 72 hours. Intracellular damage profiles were studied using fluorescence microscopy analysis with Hoechst 33342, acridine orange and propidium iodide. Results: The half-maximal inhibitory concentrations (IC50) of CDDP at 24 hours were 0.50 mM for NPC/HK-1 and 0.05 mM for C666-1. CDDP in the CDDP-TNA and chitosan-coated CDDPTNA models presented a significant degree of NPC inhibition (P<0.05) after 24, 48 and 72 hours of exposure. The outcome revealed cellular damage and shrinkage of the cell membranes after 48 hours of exposure to CDDP-TNA. Conclusion: This in vitro work demonstrated the effectiveness of TNA nanosystems for the localised CDDP treatment of NPC cells. Further in vivo studies are needed to support the findings

Surface Modification and Bioactivity of Anodic Ti6Al4V Alloy

The present study deals with surface modification of Ti6Al4V alloy via anodization technique. The morphology, structure, adhesion and bioactivity of Ti6Al4V alloy after anodization process were investigated in detail. The influence of fluoride content and direct circuit (DC) applied voltage during anodization of Ti6Al4V alloy in a bath with electrolytes composed of ethylene glycol (EG) and ammonium fluoride (NH4F) were considered. It was found that the average pore sizes and length of nanoporous or nanotubes were increasing with the fluoride content and applied voltage. A minimum of 3 wt% of NH4F is required to grow a self-organized nanotube arrays. As the fluoride content was increased to 5 wt%, TiO2 nanotubes with average diameter of 110 nm and 3.4 microm lengths were successfully synthesized. It is noteworthy to point out that the rate of the nanotube formation was increasing up to 9 microm thick bioactive TiO2 nanotubes layer as anodization time was increased to 3 h. Based on the results obtained, the PA6 cells cultured on anodic Ti6Al4V alloy showed highest level of cell viability and greater cell adhesion compared to the flat Ti6Al4V foil substrate. In fact, highly ordered nanotubes structure on Ti6Al4V alloy can provide beneficial effects for PA6 cells in attachment and proliferation

Shelf-life, bioburden, water and oxygen permeability studies of laser welded SEBS/PP blended polymer

Abstract The most common material used for blood bags is PVC, which requires the addition of DEHP to increase its flexibility. DEHP is known to cross the polymer barrier and move into the stored blood and, ultimately, the patient's bloodstream. In this work, an alternative prototype composed of SEBS/PP was fabricated through blow-moulding and compared with the commercially available PVC-based blood bag which was designated as the control. The blow-moulded sample layers were welded together using CO2 lasers and optimized to obtain complete sealing of the sides. The samples' performance characteristics were analyzed using water permeability, oxygen permeability, shelf-life, and bioburden tests. The SEBS/PP sample exhibited the highest oxygen permeability rate of 1486.6 cc/m2/24 h after 40 days of ageing, indicating that the sample is conducive for red blood cell (RBC) respiration. On the other hand, the SEBS/PP sample showcased a lower water permeability rate of 0.098 g/h m2 after 40 days of aging, indicating a high-water barrier property and thus preventing water loss during storage. In comparison, the oxygen and water permeability rates of PVC-DEHP were found to be distinctly lower in performance (662.7 cc/m2/24 h and 0.221 g/h m2, respectively). In addition, shelf-life analyses revealed that after 40 days of ageing, polymer samples exhibited no visual damage or degradation. The optimal parameters to obtain adequate welding of the SEBS/PP were determined to be power of 60% (18 W), speed of 70 in/sec and 500 Pulse Per Inch (PPI). Furthermore, the bioburden estimates of SEBS/PP of 115 CFU are markedly lower compared to the bioburden estimate of PVC-DEHP of 213 CFU. The SEBS/PP prototype can potentially be an effective alternative to PVC-based blood bags, particularly for high-risk patients in order to reduce the likelihood of medical issues

Biodegradable potential of LLDPE/TiO2-ZnO film in soil and hydrolytic systems targeted for healthcare-related product

Medical-grade polymers present challenges in long-term healthcare waste management due to resistance in degradation mechanisms. Collaborative nanocomposite technology in biomedical polymers holds promise for enhancing biodegradability. This study examined the biodegradability of LLDPE/TiO2-ZnO film in various environmental conditions (compost soil, pond soil, coastline, and landfill soil, hydrolytic and simulated body fluid models) and further assessment using field emission scanning electron microscopy (FESEM) and Coupled Plasma Optical Emission spectroscopy. Nanocomposite present in LLDPE polymer could enhance the biodegradability potential of the film possibility via hydrolysis and free radicals’ activities, especially in high moisture content environment. Deformation holes in the film were observed via FESEM confirming degradability activities. The biodegradability rate is also could be influenced by microbe-rich environments. The insights gained from this study have the potential to contribute to the advancement of biodegradable polymers and the improvement of waste management technology in the healthcare industry

Double-edged sword of biofouling potentials associated with haemocompatibility behaviour: titania nanotube arrays for medical implant surface technology

Abstract Background Medical implant failures are frequently associated with limitations of the surface technology that lead to biofouling and haemocompatibility issues. Titania nanotube array technology could provide a solution for this existing limitation. The present study describes the biofouling potential using the simulated body fluid model according to ISO 23317-2007 and haemocompatibility profiles according to ISO 10993-4 guidelines. Further haemocompatibility profiles were also assessed by evaluating full blood count, coagulation assays, haemolytic rate, whole blood clotting factor, platelet profiles, and FESEM characterization. Result Titania nanotube array nanosurface was found to present with better apatite biofouling and hydrophilic potential compared to bare titanium foil. Furthermore, good compatibility behaviour was observed based on the haemocompatibility profiles where no signs of thrombogenesis and haemolysis risks were observed. Titania nanotube array reduced fibrinogen adsorption, red blood cell and platelet adhesion and activation, which could be associated with detrimental biofouling properties. Conclusion Titania nanotube array could possess a double-edged sword of biofouling potentials that resist detrimental biofouling properties associated with thrombogenesis and haemolysis risk. It also provides better apatite biofouling potential for improved tissue and osseointegration activities. Knowledge from this study provides a better understanding of medical implant surface technology. Graphical Abstrac

Bacteriostatic Activity of LLDPE Nanocomposite Embedded with Sol–Gel Synthesized TiO2/ZnO Coupled Oxides at Various Ratios

Metal oxide-polymer nanocomposite has been proven to have selective bactericidal effects against the main and common pathogens (Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli)) that can cause harmful infectious diseases. As such, this study looked into the prospect of using TiO2/ZnO with linear low-density polyethylene (LLDPE) to inactivate S. aureus and E. coli. The physical, structural, chemical, mechanical, and antibacterial properties of the nanocomposite were investigated in detail in this paper. The production of reactive species, such as hydroxyl radicals (&bull;OH), holes (h+), superoxide anion radicals (O2&bull;&macr;), and zinc ion (Zn2+), released from the nanocomposite were quantified to elucidate the underlying antibacterial mechanisms. LLDPE/25T75Z with TiO2/ZnO (1:3) nanocomposite displayed the best performance that inactivated S. aureus and E. coli by 95% and 100%, respectively. The dominant reactive active species and the zinc ion release toward the superior antibacterial effect of nanocomposite are discussed. This work does not only offer depiction of the effective element required for antimicrobial biomedical appliances, but also the essential structural characteristics to enhance water uptake to expedite photocatalytic activity of LLDPE/metal oxide nanocomposite for long term application