Biocompatibility Tests Research Articles

A novel hydrogel orthotopic injection model in moderately hypofractionated radiation therapy for prostate cancer: Adaptive degradation and durable imaging.

Moderately hypofractionated radiotherapy (MHRT) holds an important position in prostate cancer management. Existing hydrogel spacers can protect the rectum from radiation damage, but need improvement. We explored the application of a novel hydrogel in MHRT with adaptive degradation and durable imaging functions. The hydrogels were irradiated with 6MV x-ray to detect the radio-resistance property. Male SD rats (n=45) underwent hydrogel injection between the prostate and rectum. CT was used for investigating the novel spacer's degradation and imaging functions over three months. The hydrogel's radiation-attenuation properties and biocompatibility were further assessed. Hydrogel weight and volume remained stable for six weeks post-injection. After MHRT ended, the hydrogel showed accelerated degradation characteristics and remained in the body for at most three months. CT values of hydrogels exceeded 300 Hounsfield units (HU) throughout treatment, significantly higher than in surrounding normal tissues. A significant dose drop behind the hydrogel was observed post-implantation. Biocompatibility tests of hydrogel found it safe enough for living organisms. The novel hydrogel application was fully adaptable to prostate cancer MHRT modalities, largely stable during treatment, rapidly degraded after radiotherapy ended, and consistently maintained superior imaging performance and biocompatibility. This novel spacer will be an effective tool in the era of hypofractionated radiotherapy.

Exploring Physical Characterization and Different Bio-Applications of Elaeagnus angustifolia Orchestrated Nickel Oxide Nanoparticles.

Elaeagnus angustifolia (EA) mediated green chemistry route was used for the biofabrication of NiONPs without the provision of additional surfactants and capping agents. The formation of NiONPs was confirmed using advanced different characterization techniques such as Scanning electron microscopy, UV, Fourier transmission-infrared, RAMAN, and energy dispersal spectroscopic and dynamic light scattering techniques. Further, different biological activities of EA-NiONPs were studied. Antibacterial activities were performed using five different bacterial strains using disc-diffusion assays and have shown significant results as compared to standard Oxytetracycline discs. Further, NiONPs exhibited excellent antifungal performance against different pathogenic fungal strains. The biocompatibility test was performed using human RBCs, which further confirmed that NiONPs are more biocompatible at the concentration of 7.51-31.25 µg/mL. The antioxidant activities of NiONPs were investigated using DPPH free radical scavenging assay. The NiONPs were demonstrated to have much better antioxidant potentials in terms of % DPPH scavenging (93.5%) and total antioxidant capacity (81%). Anticancer activity was also performed using HUH7 and HEP-G2 cancer cell lines and has shown significant potential with IC50 values of 18.45 μg/mL and 14.84 μg/mL, respectively. Further, the NiONPs were evaluated against Lesihmania tropica parasites and have shown strong antileishmanial potentials. The EA-NiONPs also showed excellent enzyme inhibition activities; protein kinase (19.4 mm) and alpha-amylase (51%). In conclusion, NiONPs have shown significant results against different biological assays. In the future, we suggest various in vivo activities for EA-NiONPs using different animal models to further unveil the biological and biomedical potentials.

Poly (Methyl Methacrylate)-Containing Silver-Phosphate Glass Exhibits Potent Antimicrobial Activity without Deteriorating the Mechanical and Biological Properties of Dental Prostheses.

Poly (methyl methacrylate) (PMMA) is a commonly used denture material with poor antimicrobial effects. This study investigated the antimicrobial effects of PMMA-containing silver-phosphate glass. We fabricated a novel material comprising PMMA-containing silver-phosphate glass. Then, microhardness, flexural strength, and gloss unit were analyzed. Antimicrobial activity against Streptococcus mutans and Candida albicans was investigated. Colony-forming units were counted, and antimicrobial rates were measured. Biocompatibility tests were performed using a colorimetric MTT assay for evaluating cell metabolic activity. The microhardness, flexural strength, and gloss unit of the experimental groups (with silver-phosphate glass) were not significantly different from those of the control group (no silver-phosphate glass) (P > 0.05), which showed clinically valid values. With increasing proportions of silver-phosphate glass, the antimicrobial activity against the two microorganisms increased (P < 0.05). Furthermore, S. mutans showed more than 50% antimicrobial activity in 4%, 6%, and 8% experimental groups, C. albicans showed more than 50% antimicrobial activity in 6% and 8% groups, and a statistically significant difference in antimicrobial activity was observed compared to the control (P < 0.05). The cell viability of the experimental groups was not significantly different from that of the control group (P > 0.05). Both control and experimental groups showed approximately 100% cell viability. These results suggest that silver-phosphate glass is a promising antimicrobial material in dentistry.

Wire arc additive manufacturing of commercially pure titanium bio-medical alloy

Metal additive manufacturing deploys metallic powder or wire as a feedstock to fabricate metallic parts by direct fusion in a layer-by-layer manner. Wire feedstock-based additive manufacturing provides certain advantages such as a higher rate of deposition, high density, and lower material wastage with less capital required. This study reports the Wire Arc Additive Manufacturing (WAAM) of Commercially Pure Titanium (CP Ti) and its microstructure, mechanical properties, and biocompatibility. A single-track deposition is performed to know the optimum parameters for wall structure deposition. The heat treatment is carried out to achieve desired phase transformation followed by Laser Shock Peening (LSP) as post-processing. The as-built samples showed dominant α-phase + β-phase while the content of β-phase increased after heat treatment at 900 °C. the thickness of LSP affected layer is observed to be 43.4476 µm along the cross-section. The hardness reduced after heat treatment and increased after LSP post processing. LSPed zone exhibited higher average hardness of ∼ 225 HV while that of the 30 min and 90 min heat treated samples is ∼ 180 HV0.1 and ∼ 160 HV0.1, respectively. A better antibacterial test is performed to study the inhibition zone on samples. The LSPed sample surface in the biocompatibility test. The LSPed samples showed better antibacterial effect.

The enhanced properties and bioactivity of poly-ε-caprolactone/poly lactic-co-glycolic acid doped with carbonate hydroxyapatite-egg white.

Synthetic polymers, such as PCL and PLGA, are among the main material choices in tissue engineering because of their stable structures and strong mechanical properties. In this study, we designed polycaprolactone (PCL)/polylactic-co-glycolate acid (PLGA) nanofibers doped with carbonate hydroxyapatite (CHA) and egg white (EW) with enhanced properties. The addition of CHA and EW significantly influenced the properties and morphology of PCL/PLGA nanofibers; whereby the CHA substitution (PCL/PLGA/CHA) greatly increased the mechanical properties related to the Young's modulus and EW doping (PCL/PLGA/CHA/EW) increased the elongation at break. Bioactivity tests of PCL/PLGA/CHA/EW after immersion in the SBF for 3 to 9 days showed increased fiber diameters and a good swelling capacity that could improve cell adhesion, while biocompatibility tests with NIH-3T3 fibroblast cells showed good cell proliferation (85%) after 48 h and antibacterial properties against S. aureus.

Flexible triboelectric nanogenerators using transparent copper nanowire electrodes: energy harvesting, sensing human activities and material recognition.

Triboelectric nanogenerators (TENGs) have emerged as a promising green technology to efficiently harvest otherwise wasted mechanical energy from the environment and human activities. However, cost-effective and reliably performing TENGs require rational integration of triboelectric materials, spacers, and electrodes. The present work reports for the first time the use of oxydation-resistant pure copper nanowires (CuNWs) as an electrode to develop a flexible, and inexpensive TENG through a potentially scalable approach involving vacuum filtration and lactic acid treatment. A ∼6 cm2 device yields a remarkable open circuit voltage (Voc) of 200 V and power density of 10.67 W m-2 under human finger tapping. The device is robust, flexible and noncytotoxic as assessed by stretching/bending maneuvers, corrosion tests, continuous operation for 8000 cycles, and biocompatibility tests using human fibroblast cells. The device can power 115 light emitting diodes (LEDs) and a digital calculator; sense bending and motion from the human hand; and transmit Morse code signals. The robustness, flexibility, transparency, and non-cytotoxicity of the device render it particularly promising for a wide range of energy harvesting and advanced healthcare applications, such as sensorised smart gloves for tactile sensing, material identification and safer surgical intervention.

Development and Evaluation of Novel Alginate-based Photocrosslinkable Tissue Adhesive: An In-vitro Study

Introduction: In clinical practice, traditional methods like sutures and staples are employed to halt bleeding and expedite wound healing. However, these techniques, which involve piercing tissue, come with drawbacks including the risk of inflammation, infections, and the formation of scars. Surgical sealants and tissue adhesives offer a way to mitigate some of these disadvantages associated with conventional sutures and staples. Tissue adhesives have emerged as a newer alternative for non invasive wound closure. Aim: To develop and analyse the properties of alginate-based photocrosslinkable tissue adhesive. Materials and Methods: This in-vitro analysis was done at the Department of Periodontology, Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai, India from April 2022 to May 2022. The tissue adhesive was prepared by mixing Alginate, N-Hydroxysuccinamide (NHS) and 1-Ethyl, 3- Dimethylaminopropyl Carbodiimide (EDC) and methacrylate which was used as photo initiator. The preparation was followed by characterisation of the material, strength test and evaluation of biocompatibility. Results: Surface characteristics test showed homogeneous slices in Scanning Electron Microscope (SEM) analysis. Mechanical test compressive strain was found to be 3% for both the specimens whereas tensile strain was 211.40% and 269.50% for specimen 1 and 2, respectively. Biocompatibility test of the newly developed adhesive showed that adhesive caused the L929 cells to multiply less than the fibrin glue. Conclusion: All these results suggested that the developed material is a promising soft tissue adhesive for various applications in dentistry.

A novel 3D printed type II silk fibroin/polycaprolactone mesh for the treatment of pelvic organ prolapse.

Pelvic organ prolapse (POP) is one of the common diseases in middle-aged and elderly women, caused by weakened pelvic floor muscle ligament tissue support. Pelvic floor reconstruction with mesh implantation has been proven to be an effective treatment for POP. However, traditional non-degradable and inflexible pelvic floor implantation meshes have been associated with pain, vaginal infections, and the need for additional surgeries. In this study, novel meshes with pre-designed structures were fabricated with solution-based electrohydrodynamic printing (EHDP) technology, using a series of polycaprolactone/silk fibroin composites as bioinks. The PCL/SF mesh mechanical performances were particularly enhanced with the addition of silk II, leading it to obtain higher adaptability with soft tissue repair. The mesh containing SF showed more robust degradation performance in the in vitro degradation assay. Furthermore, biocompatibility tests conducted on mouse embryonic fibroblasts (NIH/3T3) revealed enhanced cell affinity. Finally, the biocompatibility and tissue repair properties of PCL/SF mesh were verified through the implantation of meshes in the muscle defect site of mice. The results demonstrated that the 3D printed PCL/SF mesh prepared by EHDP exhibits superior mechanical properties, biocompatibility, biodegradability, as well as ligament and muscle fiber repair ability. The novel implantable meshes are promising for curing POP.

Electrospun poly(3-hydroxybutyrate-co-3-hydroxyvalerate) scaffolds – a step towards ligament repair applications

ABSTRACT The incidence of anterior cruciate ligament (ACL) ruptures is approximately 50 per 100,000 people. ACL rupture repair methods that offer better biomechanics have the potential to reduce long term osteoarthritis. To improve ACL regeneration biomechanically similar, biocompatible and biodegradable tissue scaffolds are required. Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), with high 3-hydroxyvalerate (3HV) content, based scaffold materials have been developed, with the advantages of traditional tissue engineering scaffolds combined with attractive mechanical properties, e.g., elasticity and biodegradability. PHBV with 3HV fractions of 0 to 100 mol% were produced in a controlled manner allowing specific compositions to be targeted, giving control over material properties. In conjunction electrospinning conditions were altered, to manipulate the degree of fibre alignment, with increasing collector rotating speed used to obtain random and aligned PHBV fibres. The PHBV based materials produced were characterised, with mechanical properties, thermal properties and surface morphology being studied. An electrospun PHBV fibre mat with 50 mol% 3HV content shows a significant increase in elasticity compared to those with lower 3HV content and could be fabricated into aligned fibres. Biocompatibility testing with L929 fibroblasts demonstrates good cell viability, with the aligned fibre network promoting fibroblast alignment in the axial fibre direction, desirable for ACL repair applications. Dynamic load testing shows that the 50 mol% 3HV PHBV material produced can withstand cyclic loading with reasonable resilience. Electrospun PHBV can be produced with low batch variability and tailored, application specific properties, giving these biomaterials promise in tissue scaffold applications where aligned fibre networks are desired, such as ACL regeneration.

Fabrication of Biodegradable and Biocompatible Functional Polymers for Anti-Infection and Augmenting Wound Repair

The problem of bacteria-induced infections threatens the lives of many patients. Meanwhile, the misuse of antibiotics has led to a significant increase in bacterial resistance. There are two main ways to alleviate the issue: one is to introduce antimicrobial agents to medical devices to get local drug releasing and alleviating systemic toxicity and resistance, and the other is to develop new antimicrobial methods to kill bacteria. New antimicrobial methods include cationic polymers, metal ions, hydrophobic structures to prevent bacterial adhesion, photothermal sterilization, new biocides, etc. Biodegradable biocompatible synthetic polymers have been widely used in the medical field. They are often used in tissue engineering scaffolds as well as wound dressings, where bacterial infections in these medical devices can be serious or even fatal. However, such materials usually do not have inherent antimicrobial properties. They can be used as carriers for drug delivery or compounded with other antimicrobial materials to achieve antimicrobial effects. This review focuses on the antimicrobial behavior, preparation methods, and biocompatibility testing of biodegradable biocompatible synthetic polymers. Degradable biocompatible natural polymers with antimicrobial properties are also briefly described. Finally, the medical applications of these polymeric materials are presented.

From Basic Science to Clinical Perfection: What Defines the Orthopedic Biocompatible Implant?

The general improvement in life expectancy and standard of living makes it easier for patients to get access to routine medical exams and is anticipated to increase the prevalence of several degenerative joint illnesses. In addition, it is anticipated that their incidence will increase both nationally and internationally, which will raise the demand for novel and long-lasting implantable devices in the field of orthopedics. The current review’s goals are to define what constitutes a biocompatible orthopedic implant in terms of in vitro biocompatibility testing and to clarify important concepts and definitions that are already in use. The demand for materials and implants made of various tissues is now increasing, and the ongoing advancement of in vitro cell culture studies is a reliable practical tool for examining the biocompatibility of potential implantable materials. In vitro biocompatibility research has been reduced and, in most cases, diminished to laboratory studies that no longer or drastically reduce animal sacrifice as a response to the well-known three “Rs” (“reduction”, “refinement”, and “replacement”) introduced to literature by English academics in the 1960s. As technology advances at an astounding rate, a new generation of gene-activating biomaterials tailored for specific people and disease conditions might emerge in the near future.

Simultaneous extraction of calcium phosphates and proteins from fish bones. Innovative valorisation of food by-products

By-products of the fish industry can be a source of valuable molecules, with different technological applications. Fish bones contain both organic and inorganic phases (collagen/other proteins and calcium phosphate minerals respectively), with several uses and among them in cosmetics and medicine. Using the common extraction protocols, only one of the two phases can be extracted, while the other one is degraded. In the present work a method of extraction which allows the obtainment of both proteins and calcium phosphates was developed. Bones from two different species (salmon and sea bream) were tested. Saline solutions based on (NH4)HCO3/(NH4)2HPO4 or (NH4)HCO3 were employed for the protein extraction. Analysis of the organic phase showed that the main extracted proteins were collagen in its different forms (especially α-1); some differences were observed between salmon and sea bream and between the methods of extraction. As for the mineral phase, after calcination at 700 °C, single phase hydroxyapatite was obtained with (NH4)HCO3 solution, while the use of (NH4)HCO3/(NH4)2HPO4 led to a biphasic material of β-tricalcium phosphate and β-calcium pyrophosphate. Biocompatibility tests performed on both organic and inorganic extracts (with fibroblast and osteoblast-like cellular lines) showed their non-toxicity and, hence, their potential suitability for cosmetic or biomedical applications. This work shows that it is possible to obtain a more complete valorisation of the fish bones, with the simultaneous extraction of organic and inorganic valuable compounds. The principles of this process could be applied also to bones of other species, with a positive impact on the environment for the reduction of the wastes and a better use of all available resources.

Effective self-charge boosting sweat electrolyte textile supercapacitors array from bio-compatible polymer metal chelates

Planar structured sweat electrolyte textile supercapacitors made from biocompatible polymer metal chelates with effectively boosts their own self-charge. We have investigated sweat electrolyte based energy storage devices that use cotton fabric placed on the skin to achieve effective self-charge boosting and high flexible textile-supercapacitors. Poly3,4-ethylenedioxythiophene: Tris (2-aminoethyl)amine: Manganese oxide@manganese carbonates (PEDOT:TREN:MnO2@MnCO3) matrix hydrogel adorned electrodes. Hydrothermal synthesis employed with active materials under 1-Butyl-3-methylimidazolium tetrafluoroborate (BMIMBF4) as a solvent. Physiochemical properties and surface morphological features are explored. Mn 2p1/2 (653.2 eV), Mn 2p3/2 (641.3 eV), N1s (401.4 eV), and C1s (401.4 eV) peaks are all present and predicted in the XPS profiles of the composite (285.3 eV). In a state of perspiration, the textile supercapacitor's capacitance is 30 Fcm−2 and this performance preserves 92% of their early performances afterwards 50,000 charge-discharge series, and they also showed remarkable specific capacitance at large area device in real time performance. It is promising good results in biocompatibility tests. To test the sweat dilution with water for a wearable smart and textile-based energy storage device also performed well, this sweat-based textile-supercapacitor could be good candidates to start fabrication or printing e textile embed energy storage system.

Titanium Membranes with Hydroxyapatite/Titania Bioactive Ceramic Coatings: Characterization and In Vivo Biocompatibility Testing.

Titanium membranes and meshes are used for the repair of trauma, tumors, and hernia in dentistry and maxillofacial and abdominal surgery. But such membranes demonstrate the limited effectiveness of integration in recipients due to their bioinertness. In this study, we prepared titania oxide (by microarc oxidation) and/or HAp (by electrophoresis deposition) coatings with alginate soaking. We used annealing at 700 °C for 2.5 h for HAp crystallinity increasing with achievement of an acceptable Ca2+ release rate. The feedstock HAp and prepared coatings were characterized by X-ray diffraction, IR spectroscopy, electron and optical confocal microscopy, and thermal analysis, as well as the in vitro study of solubility in saline and in vivo tests with the animal model of subcutaneous implantation (with Wistar rats). Biocompatible compounds were found for all deposited coatings. We noted that the best biological response was detected for the annealed Ca-P/TiO2 bilayer with alginate binding. In this case, the coating crystallinity was ≈40.5-50.0%. The Ca2+ release rate was 2.042 ± 0.058%/mm2 at 168 h after immersion in saline. Thin and mature tissue capsules with minimal inflammation and vascularization were found in histological sections. We did not detect any unwanted responses around the implants, including inflammation infiltration, suppuration, bacterial infections, tissue lyses, and, finally, implant rejection. This information is expected to be useful for understanding the properties of bioactive ceramic coatings and improving the quality of medical care in dentistry and maxillofacial surgery and other applications of titanium membranes in medicine.

Topical Sustained Delivery of Miltefosine Via Drug-Eluting Contact Lenses to Treat Acanthamoeba Keratitis.

This study aimed to develop a miltefosine-eluting contact lens (MLF-CL) device that would allow sustained and localized miltefosine release for the treatment of Acanthamoeba keratitis. MLF-CLs were produced in three different miltefosine doses by solvent-casting a thin miltefosine-polymer film around the periphery of a methafilcon hydrogel, which was then lathed into a contact lens. During seven days of in vitro testing, all three formulations demonstrated sustained release from the lens at theoretically therapeutic levels. Based on the physicochemical characterization of MLF-CLs, MLF-CL's physical properties are not significantly different from commercial contact lenses in terms of light transmittance, water content and wettability. MLF-CLs possessed a slight reduction in compression modulus that was attributed to the inclusion of polymer-drug films but still remain within the optimal range of soft contact lenses. In cytotoxicity studies, MLF-CL indicated up to 91% viability, which decreased proportionally as miltefosine loading increased. A three-day biocompatibility test on New Zealand White rabbits revealed no impact of MLF-CLs on the corneal tissue. The MLF-CLs provided sustained in vitro release of miltefosine for a week while maintaining comparable physical features to a commercial contact lens. MLF-CL has a promising potential to be used as a successful treatment method for Acanthamoeba keratitis.

Acellular Nipple Scaffold Development, Characterization, and Preliminary Biocompatibility Assessment in a Swine Model.

The standard in nipple reconstruction remains the autologous skin flap. Unfortunately, the results are not satisfying, with up to 75% loss of nipple projection over time. Existing studies investigated the use of primates as a source of implants. The authors hypothesized that the porcine nipple can serve as a perfect shape-supporting implant because of functional similarities to the human nipple. A decellularization protocol was developed to obtain an acellular nipple scaffold (ANS) for nipple reconstruction. Tissue samples were collected from eight disease-free female Yorkshire pigs (60 to 70 kg) and then decellularized. The decellularization efficiency and extracellular matrix characterization was performed histologically and quantitatively (DNA, total collagen, elastin, and glycosaminoglycan content). In vitro and in vivo biocompatibility was determined by human dermal fibroblast culture and subcutaneous implantation of six ANSs in a single Yorkshire pig (60 to 70 kg), respectively. Inflammation and adverse events were monitored daily based on local clinical signs. The authors showed that all cellular structures and 96% of DNA [321.7 ± 57.6 ng DNA/mg wet tissue versus 11.7 ± 10.9 ng DNA/mg wet tissue, in native and ANS, respectively ( P < 0.001)] can be successfully removed. However, this was associated with a decrease in collagen [89.0 ± 11.4 and 58.8 ± 9.6 μg collagen/mg ( P < 0.001)] and elastin [14.2 ± 1.6 and 7.9 ± 2.4 μg elastin/mg ( P < 0.05)] and an increase in glycosaminoglycan content [5.0 ± 0.7 and 6.0 ± 0.8 ng/mg ( P < 0.05)]. ANS can support continuous cell growth in vitro and during preliminary biocompatibility tests in vivo. This is a preliminary report of a novel promising ANS for nipple reconstruction, but more research is needed to validate results. Breast cancer is very common among women. Treatment involves mastectomy, but its consequences affect patient mental well-being, and can lead to depression. Nipple-areola complex reconstruction is critical, and existing methods lead to unsatisfactory outcomes.

Room-temperature rapid self-assembled biocompatible MOFs as an Instant, temporary tooth sealant

• Rapid synthesis of M-Tartaric acid (M = Zn, Mn) MOFs after combinatory test. • Instant coating of M-Tartrate in primary human teeth. • Tooth enamel surface analysis after coating & brushing using SEM EDS. • In-vitro Biocompatibility test conducted using neuronal stem cel. Tooth discoloration is a commonly occurring phenomenon, due to adsorption of coloring substances inside the pores of tooth enamel. In this research, we developed a Room-Temperature Rapid Self-assembly method for Biocompatible Metal-Organic Framework(MOF) sealants. We experimented using combinations between two metal acetates(Zn, Mn) and three types of ligands commonly known to be unharmful to humans(L-(+)-Tartaric acid, l -Glutamic acid, l -Aspartic acid), resulting in development of crystalline materials between Zn-Tartaric acid and Mn-Tartaric acid. The products were characterized by X-ray Diffraction(XRD), Infrared Analysis(IR), Differential Scanning Calorimetry(DSC), Thermogravimetric Analysis(TGA), confirming the formation of MOFs. We also conducted a biocompatibility test using neural stem cells for the MOFs and its reactants, concluding that Zn-Tartrate could be safely used at 7.5 µg/mL concentration, preserving approximately 95 % cell viability. Then, we confirmed the availability of tooth coating of both MOFs using primary human teeth, and experimented the prevention of tooth discoloration by immersing the coated teeth in beverage that contain coloring substances; Cola, Red Wine, Coffee. Finally, we measured the amount of metal element remaining on the surface of the tooth after brushing by Scanning Electron Microscope(SEM), Energy Dispersive X-ray Spectroscopy(EDS), concluding that Zn-Tartrate is the optimal MOF for temporary tooth sealants. Furthermore, we opened a new possibility for rapid synthesis of biocompatible coating, and the mass production of biocompatible MOFs that can be utilized in the biomedical field.

Assessing biocompatibility & mechanical testing of 3D-printed PEEK versus milled PEEK

ObjectivesTo compare mechanical properties of 3D-printed and milled poly-ether-ether-ketone (PEEK) materials. To define post-production treatments to enhance biocompatibility of 3D-printed PEEK. MethodsStandardised PEEK samples were produced via milling and fused-deposition-modelling 3D-printing. To evaluate mechanical properties, tensile strength, maximum flexural strength, fracture toughness, and micro-hardness were measured.3D printed samples were sandblasted with 50 or 125 μm aluminium oxide beads to increase biocompatibility.Scanning electron microscopy (SEM) evaluated microstructure of 3D-printed and sandblasted samples, estimating surface roughness at scales from 1mm-1μm.Cell adhesion on 3D printed and sandblasted materials was evaluated by culturing primary human endothelial cells and osteoblasts (HUVEC, HOBS) and evaluating cell growth over 48 h. Results3D printed materials had lower tensile strength, flexural strength, and fracture toughness, but higher micro-hardness.SEM analysis of 3D-printed surfaces showed sandblasting with 125 and 50 μm silica particles removed printing defects and created roughened surfaces for increased HUVEC and HOBs uniform cell adhesion and distribution. No cytotoxicity was observed over a 48h period, and all cells demonstrated >95% viability. Clinical significance3D-printing of PEEK is an emerging technology with clear advantages over milling in maxillofacial implant production. Nonetheless, this manufacturing modality may produce 3D printed PEEK devices with lower mechanical resistance parameters compared to milled PEEK but with values compatible with natural bone. PEEK has poor osteoconductivity and ability to osseointegrate. Sandblasting is an inexpensive modality to remove irregular surface defects and create uniform micro-rough surfaces supporting cell attachment and potentially enhancing integration of PEEK implants with host tissue.

An investigation of IRMOF-16 as a pH-responsive drug delivery carrier of curcumin

Metal-organic frameworks (MOFs) with tunable structures, high porosity, and abundant active sites are considered to be promising drug delivery systems (DDSs). In this study, novel MOFs-based nanoparticles (CUR@IRMOF-16) were successfully prepared using Zn-based IRMOF-16 as a carrier, and curcumin (CUR) as the model drug. This nanocargo delivery platform has dual capabilities, enabling simultaneous drug delivery and fluorescence imaging. In vitro release experiments showed that nanoparticles were released more quickly under mildly acidic conditions, which proved their potential for tumor microenvironment-responsive drug release. Through in vitro cell experiments, it was found that the nano-drug platform had high antitumor cytotoxicity, which may be related to the mechanism of increasing intracellular reactive oxygen species (ROS), reducing intracellular mitochondrial membrane potential (MMP), and inducing apoptosis. In addition, confocal laser microscopy showed that CUR@IRMOF-16 could localize to the nucleus to exert an antitumor effect. Meanwhile, CUR@IRMOF-16 exhibited superior antitumor activity compared with pure CUR in vitro experiments. The biocompatibility test of IRMOF-16 showed reasonable biosafety, and no evidence of obvious toxicity was observed in vitro. CUR@IRMOF-16 has unique advantages with regard to pH response, biocompatibility, and antitumor efficacy, indicating that the nano-drug platform is a promising drug delivery carrier with an antitumor effect.

Improving the Corrosion Resistance of TNTZ in Hanks’ Solution after Thermomechanical Treatment

Ti-29Nb-13Ta-4.6Zr (TNTZ) is a new titanium alloy potentially to be used as bone implant material because of its advantages in terms of strength, ductility, non-toxicity, corrosion resistance, and biocompatibility. Its mechanical properties are suitable for bone applications; however, there are still problems related to its corrosion behavior when used for a long time. Therefore, this research aims to determine the corrosion rate and types, and provide corrosion prevention by applying the thermomechanical treatment on TNTZ in Hanks’ solution. The limitation of this research was in not conducting the TNTZ biocompatibility tests. This research was conducted using the potentiodynamic polarization method in Hanks’ solution as the corrosive medium at a temperature of 37°C and a pH of 6.8. Before corrosion testing, a TNTZ sample was treated with thermomechanical treatment combined with solution treatment at a temperature of 850°C and a holding time of 45 minutes, followed by rapid cooling (water quenching), and plastic deformation with deformation variations of 10%, 15%, and 20%, and it was ended with aging heat treatment at a temperature of 300°C and holding time for 1 hour. The novelties of this research are the valid data of corrosion rate and type of TNTZ, which were unavailable before, and corrosion prevention through thermomechanical treatment of TNTZ in Hanks’ solution. The thermomechanical treatment is proved to reduce the pitting corrosion in TNTZ. The results show that thermomechanical treatment and increased plastic deformation can reduce the value of the corrosion rate, as evidenced by the pre-thermomechanical and thermomechanical TNTZ corrosion rates with deformation variations of 10%, 15%, and 20%, respectively, which were 5.522 x 10-4 mmpy; 2.754 x 10-4 mmpy; 2.290 x 10-4 mmpy; and 2.064 x 10-4 mmpy, respectively. TNTZ, after thermomechanical treatment, had the lowest corrosion rate, i.e., 2.064 x 10-4 mmpy, while Ti-6Al-7Nb had the highest one, i.e., 3.05 x10-2 mmpy. The type of TNTZ corrosion is pitting corrosion, as shown by the loss of zirconium that reduced the volume, causing pits to occur. Meanwhile, after thermomechanical treatment, pitting corrosion happened on TNTZ because of the loss or release of zirconium. This research shows that after thermomechanical treatment, TNTZ is the best material compared to other materials for biomedical applications based on corrosion resistance.