Aim: To demonstrate a simple, eco-friendly, and cost-effective green method to synthesize gold nanoparticles (AuNPs) using the aqueous extract of gum Arabic (GA) as a reducing and stabilizing agent. Methods: Green synthesis of nanoparticles, characterization by absorption, infra-red and fluorescence spectroscopy. Results: The absorption spectrum (UV-Vis) showed an absorption peak ~522 nm corresponding to the surface plasmon resonance (SPR) absorption peak of AuNPs. Transmission electron microscopy (TEM) images revealed spherical-shaped nanoparticles with an average size of 15 nm. Fourier transform infrared (FTIR) analysis showed that the nanoparticles are coated with organic compounds that are present in GA. The fluorescence quenching properties of the AuNPs were assessed by monitoring their effects on fluorescence intensity of coumarin 153 (C153) dye. The fluorescence of the dye decreased with an increase in concentration of the nanoparticles. Upon addition of the protein bovine serum albumin (BSA) to the mixture the fluorescence increased (recovery) again. Conclusions: The fluorescence quenching and recovery (turn-on/off system) is a valuable method for protein detection in solution. By observing the effect of BSA on the quenched fluorescence, this nanoparticle system shows promise in biomedicine, drug delivery and environmental monitoring.

Aim: The study aims to analyze the canine’s implant behaviour under compressive loading [to be installed in a maxilla at a premolar 4 (PM4) location]. After simulation of various mechanical properties, the 17-4 precipitate hardened (PH) stainless steel (SS) prototypes were successfully 3D printed by powder bed fusion (PBF) process with solid and octet metastructure to reduce stress shielding. Methods: The maxillary PM4 tooth of a male German shepherd dog was selected as the subject for the proposed study. As PM4 loading in canines is analogous to compressive loading conditions, finite element analysis (FEA) under compression was performed to compare simulated results of solid and octet metastructure specimens. Solid and octet meta structure-based compression samples were prepared per ASTM E9 standard using SolidWorks software. The octet metastructure was designed with node and connector diameters of 0.5 mm each on 3DXpert software. Further FEA analysis of designed compression samples was performed using Ansys Workbench by selecting 17-4PH SS material at loading conditions of 800 N and 5,000 N. Results: The FEA results at the loading of 800 N show that maximum Von-Mises stress in the case of the solid and octet meta structure-based compression specimen was 10.029 MPa and 131.61 MPa, respectively. Further, the maximum Von-Mises strain for the solid and octet meta-structure-based specimens was 0.000049163 and 0.00067179, respectively. Similarly, deformation (in mm) for solid and octet truss lattice-based compression samples were 0.00075097 and 0.001451, respectively. The results observed at the loading condition of 5,000 N followed a pattern similar to that of 800 N loading conditions. Conclusions: Octet metastructure-based compression sample showed encouraging potential for withstanding maximum compression loading applicable to canine (800 N) while lowering the impacts of stress shielding. The safety factor against failure ( N) was 4.33 and 62.31 for the octet meta-structure and solid compression samples, respectively.

Aim: This study aims to fabricate and characterise a novel tri-layer scaffold based on type I atelocollagen, hyaluronic acid (HA), and a novel fibrillar elastin gel, mimicking the native heart valve leaflets in structure, composition, and mechanical properties, among which, the bending anisotropic behaviour in both the with curvature (WC) and the against curvature (AC) directions, is the most desired. The use of atelocollagen is of significant importance in highlighting the non-antigenic potential of the design. Methods: Porous scaffolds were freeze-dried, then crosslinked using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) and N-hydroxysuccinimide (NHS). The fibrillogenesis occurrence and the scaffold microstructure were imaged using scanning electron microscopy (SEM). Fourier transform infrared spectroscopy (FITR) investigated the effect of fabrication and crosslinking on the backbone structure. Dynamic mechanical analysis (DMA) characterised the compressive and bending properties of the scaffolds in hydrated and non-hydrated states. Three-point bending and a “self-deflection” test were performed on tri-layer scaffolds in both WC and AC directions. Results: Atelocollagen-based scaffolds were successfully produced, rendering this study the first to report a tri-layer structure using atelocollagen, HA, and elastin fibrillar gel. The scaffolds’ porosity was tailored to accommodate potential future biological studies and the transition between layers appeared seamless. FITR unveiled effective crosslinking and the backbone structure preservation. The scaffolds exhibited lightly crosslinked polymer resembling mechanical responses when non-hydrated, and the desired J-curve stress-strain response was observed when hydrated. The tri-layer scaffolds showed anisotropic bending behaviour with a bending modulus of 5.41 ± 1.14 kPa (WC) and 7.98 ± 2.22 kPa (AC). Conclusions: The tri-layer scaffolds fabricated resemble the native aortic valve leaflets in structure and composition, and successfully introduced bending anisotropy in physiological conditions. Together with the suitable microstructure and promising mechanical properties, the design is reckoned to be a potential tissue engineering heart valve candidate.

The increasing number of prosthetic hip replacement surgeries and their growing indication have led to a growing interest in understanding the factors that influence their long-term success. Total hip arthroplasty (THA) failure is mainly due to aseptic loosening. More rarely septic mobilization may occur. In the first case, many variables influence the bone-implant relationship and periprosthetic bone remodeling. Stress-shielding is the most evident but not fully explained manifestation of the bone implant interaction. Recently, three-dimensional (3D) printed titanium orthopedic implants have offered new perspectives in the field of hip prosthetics, enabling the customization and production of acetabular cups with enhanced biocompatibility. This review aims to evaluate the efficacy and reliability of 3D printed acetabular cups from the perspective of aseptic failure particularly related to the stress-shielding. The most recent clinical and preclinical studies will be reviewed, exploring the benefits and challenges associated with the use of these emerging technologies. Key factors, such as biocompatibility, mechanical stability, osseointegration, and wear resistance.

Improving the performance of blood-contacting medical implants is a global health necessity aimed at reducing mortality and morbidity in patients with cardiovascular diseases. Surface modification of the biomaterials from which the vascular grafts are constructed has been used to reduce the risk of complications such as thrombosis and infection. Herein with a focus on vascular tissue engineering, we provided an overview of (a) fundamental hemodynamic considerations for blood-contacting biomaterials, (b) surface modification strategies to attenuate nonspecific adhesion of proteins, improve hemocompatibility, and induce the formation of a confluent endothelial lining, and (c) the guidelines for the clinical development of surface modified biomaterials.

Aim: This study aims to explore the sensing capabilities of polyvinylidene fluoride-hydroxyapatite-chitosan (PVDF-HAP-CS) composite-based hernia mesh implants (of conformal/planar design), followed by in-vitro analysis for better understanding of the bio-stability in the patient’s body. Methods: For analyzing the sensing capabilities, a microstrip patch antenna (MPA)-based implantable sensor [with 17-4 precipitate hardened (PH) stainless steel (SS) (bio-compatible) and Cu alloy (non-biocompatible) materials as conducting plane/patch with PVDF-HAP-CS as dielectric material] has been considered separately in this study. Primarily, in this study, the 3D models of the hernia mesh implant have been designed in the high-frequency structure simulator (HFSS) software, and the sensing behaviour of the same has been recorded. Results: The HFSS results represent that for the 17-4PH SS-based sensor, resonant frequency (f_r) decreases from 2.3953 to 2.3800 GHz, whereas the gain increases from 0.54 to 4.02 dB with a SAR value of 1.077 W/kg. The f_r for Cu alloy increases up to 30° conformal angle and, after that, starts decreasing, whereas the gain reaches 3.24 dB with a SAR value of 1.238 W/kg. The in-vitro study highlights that both materials (17-4PH SS and Cu alloy) possess a low corrosion rate. Conclusions: The simulation-based comparison of the biosensors with conducting elements 17-4PH SS and Cu alloy for different conformal angles indicates that the 17-4PH SS shows promising results over Cu in terms of higher gain (up to 4.02 dB) and low SAR value (1.077 W/kg) with the f_r lying in the industry scientific and medical (ISM) band and therefore may be used for implantable sensor applications and possesses the capability to be used as 3D-printed hernia mesh implant. The in-vitro results with the low corrosion rate ≈ of 5.1 × 10^–8 mm/year, 17-4PH SS may be a suitable material for the fabrication of hernia mesh implant.

Aim: The purpose of this study was to digitally quantify the consistency and variation of printed resin crown patterns produced by different 3D printers, aiming to evaluate their clinical relevance and accuracy. This was accomplished by evaluating patterns manufactured using three different 3D printers and resin materials, assessing their fit and adaptation through digital scanning and analysis. The objective was to determine the internal and marginal variations of printed crown resin patterns and to identify the printer and material combinations that produce the most consistent and clinically acceptable results. Methods: A prefabricated typodont tooth was prepared for a crown and scanned using an intraoral scanner. From this scan, a crown was designed and the resulting STL file was exported. This 3D file was manufactured using resins indicated for castable patterns on 3 different printers: FotoDent® Cast with the Carbon M2 printer, Form 3 Castable with the Form 2 printer, and Siraya Tech Cast with the ELEGOO Mars 2 Pro 3D printer. Finally, the crown resin patterns were scanned using an intraoral digital scanner (3Shape TRIOS 3) scanner, and crown adaptation was digitally quantified in GeoMagic software. Clinically relevant significance was determined (marginal gap < 50 µm) between resin patterns printed on different printers. Results: Form 3 Castable/Form 2 printer had the lowest mean internal variation at all measurement areas, 21.07 μm at the occlusal, 104.23 μm at the margin, and 37.98 μm at the axial. FotoDent® Cast/Carbon M2 had the largest marginal variation while Siraya Tech Cast/ELEGOO Mars 2 Pro had the largest occlusal variation. Within each material, the largest internal variation was at the marginal area while the lowest value was in the occlusal area. Conclusions: All printed crowns displayed clinically acceptable ranges, but there was a statistically significant difference in the fit between all printers.

Aim: Synthesis of plasmonic nanoparticles, characterization, size detection by modeling. Methods: Colloidal plasmonic gold and silver nanoparticles were prepared by laser ablation with a 1,064 nm pulsed Nd:YAG laser with equal fractional volume and then were illuminated with its 532 nm second harmonic pulse. After the illumination process, we observed 1 nm blue shift in peak position of gold colloid and 4 nm blue shift in silver colloid. We observed a variation in the dielectric function due to nanoparticle size reduction in both samples. Using micrograph, size distribution was plotted and with the help of Mie theory and size dependent dielectric function, we reconstructed absorption spectrum to best fit the experimental spectrum and we estimated 12- and 16-fold increase in the number of Au and Ag nanoparticles respectively, due to illumination. Results: We have estimated size distribution of produced nanoparticles. Conclusions: We produced silver and gold colloids with ablation of their foils in water without any surfactant, and then we fragmented the nanoparticles colloids with an intense nanosecond laser and studied the effect of illumination on peak position and size distribution of colloids.

The fusion of biomaterial science with clinical practice in oculoplastic and orbital surgery, particularly in the reconstruction of the posterior lamella of the eyelid, the lacrimal system, orbital floor fractures, and the development of implants for anophthalmic sockets, represents a frontier where materials meet surgical techniques. This review, which spans research from 2015 to 2023, delves into the application and integration of biopolymers and functional biomaterials in these complex areas. The discussion begins by reviewing the key anatomy of the external ocular surface, lacrimal system, and orbit. It then summarizes the various current surgical approaches for treating diseases affecting the external ocular surface and orbital involvement, with an emphasis on the associated challenges. The discussion continues with a comprehensive overview of the advantages and disadvantages of current and emerging biomaterials, including synthetic and natural polymers, used in reconstructive surgeries. These include applications for eyelid structure reconstruction, lacrimal system repair, orbital bone fracture repair, and orbital socket reconstruction. Throughout the review, the pathophysiology and challenges associated with these reconstructive procedures are explored, with an emphasis on surgical nuances and the ongoing pursuit of optimal reconstruction techniques. Finally, this review serves as a valuable resource for familiarizing clinicians with current knowledge and generating future hypotheses. It concludes that no evidence-based guidelines currently exist in oculoplastic surgery regarding the use of biopolymers in reconstructive procedures. Further research is needed to evaluate the efficacy and reproducibility of these biopolymers.

Hydrogel-based drug delivery systems (DDS) offer promising alternatives for treating ocular diseases by overcoming the limitations of traditional therapies, such as low bioavailability, frequent administration, and invasiveness. Hydrogels, with their high biocompatibility and ability to respond to external stimuli, can provide sustained and targeted drug delivery. This review highlights the unique properties of hydrogels, including their swelling behavior, porosity, and mechanical strength, making them suitable for various ocular applications. The classification of hydrogels based on cross-linking methods, origins, and stimuli responsiveness is discussed, emphasizing their potential in drug delivery for dry eye disease (DED), glaucoma, corneal alkali burns, and neovascularization. Notable advances include thermosensitive and pH-responsive hydrogels, which have shown promising results in preclinical studies. Despite these advances, most studies are still in preclinical stages, highlighting the need for rigorous human trials to validate the safety and efficacy of hydrogel DDS. Collaborative efforts among researchers, pharmacologists, and ophthalmologists are essential to translating these innovations into clinical practice, ultimately improving patient outcomes in ocular disease management.

Nanoparticles (NPs) are at the forefront as they are providing unprecedented solutions to obstacles and issues in treating neurodegenerative diseases. Due to their size, surface characteristics, and ability to be functionalized, these carriers can directly deliver therapeutics across what is considered one of the main barriers to central nervous system (CNS) treatment, the blood-brain barrier (BBB). Through nanotechnology, anti-disease agents such as Alzheimer’s, Parkinson’s, and Huntington’s therapies become more bioavailable, specific in action, and with fewer side effects. The NPs serve as molecular carriers that facilitate transport across the BBB by receptor-mediated transcytosis or by disruption of the barrier with a view to properly delivering drugs to the neural tissues. Some of the therapeutic applications of nanotechnology also present the concept of molecular medicine since the NPs are designed to deliver drugs in accordance with specific biomolecule signals. Besides the therapeutic applications, NPs replace the traditional contrast media for magnetic resonance imaging (MRI) and positron emission tomography (PET) scans for better diagnosis as well as disease tracking in the early stages. In addition, their effects on solubility increase the therapeutic potential of earlier useless compounds, and the preservation of bioactive molecules from degradation increases the therapeutic capacity of medications. Neurodegenerative disorders are marked by oxidative stress and inflammation that contribute to the disease severity; thus, liposomes, dendrimers, and polymeric NPs encapsulate antioxidants and anti-inflammatory compounds, so they target the areas most affected by the disease. Such sophisticated systems minimize the extension of neuronal deterioration and enhance the lot of such patients. The “theranostic” NPs allow for continuous diagnosis and treatment by containing both diagnostic and therapeutic features. These have created unprecedented opportunities to meet the unmet needs in CNS disorders and may revolutionize the evolution of managing neurodegenerative diseases and innovative neuroimaging procedures in the future.

Silver iodide (AgI) nanostructures have been considered as promising candidates for optical biosensors owing to their optical characteristics of optical properties, including tunable surface plasmon resonance (SPR) and fluorescence enhancement. Such properties let one analyze biomolecules with high sensitivity, which makes them ultra-useful in diagnostics. The formed AgI nanostructures can be synthesized using chemical precipitation and template methods that enable fine-tuning of the morphology and crystallinity of the final nanostructure. The presence of SPR enhances optical signals potentially, and fluorescence enhancement helps visualize biomolecule interactions easier as the analyte concentration is usually low. Such uses of biosensors include applications in proteins, nucleic acids, and other biomolecules for progress in disease diagnosis and pharmacogenomics. Moreover, the good biocompatibility level of the created AgI nanostructures makes it possible to integrate them into biological systems safely, increasing their usage in medicine. This integration of their appealing optics, biosensing operating principles, and biocompatibility establishes their centrality in the creation of future photonic biosensors for faster, intuitive, and painless detection.