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Carbon nanotubes (CNTs) have been widely studied and used for the construction of electrochemical biosensors owing to their small size, cylindrical shape, large surface-to-volume ratio, high conductivity and good biocompatibility. In electrochemical biosensors, CNTs serve a dual purpose: they act as immobilization support for biomolecules as well as provide the necessary electrical conductivity for electrochemical transduction. The ability of a recognition molecule to detect the analyte is highly dependent on the type of immobilization used for the attachment of the biomolecule to the CNT surface, a process also known as biofunctionalization. A variety of biofunctionalization methods have been studied and reported including physical adsorption, covalent cross-linking, polymer encapsulation etc. Each method carries its own advantages and limitations. In this review we provide a comprehensive review of non-covalent functionalization of carbon nanotubes with a variety of biomolecules for the development of electrochemical biosensors. This method of immobilization is increasingly being used in bioelectrode development using enzymes for biosensor and biofuel cell applications.

Nanoparticles have immense industrial, biotechnological, and biomedical/pharmaceutical applications due to their pliability in structure, size, biocompatibility, high surface area, and versatile functionalization, which have led to their ubiquitous application in diverse areas Advancement of the science in the research field has revolutionized our lifestyle and health care from medicine to the agricultural field but there were also some negative impacts of this development apart from the benefits. Nanotechnology has been one of the ladders responsible for this revolution which has to some extent decreased the adverse effects. Among various types of nanoparticles, silica nanoparticles (SiO2 NPs) have become favoured as nanostructuring, drug delivery, and optical imaging agents. Silica nanoparticles are immensely stable, less toxic. Mesoporous silica materials with pore sizes in the range between 2 and 50 nm have attracted widespread attention due to their precisely tuneable macroscopic form, chemical functionality, and mesoporous structure. Silica has been also applied for the remediation of the environment pollutants like to carry out enhanced oil recovery to reduce the liberation of brine, heavy metals and radioactive compounds into water, removal of metals, non-metals and radioactive elements,water purification. This article reviews the important applications of silica nanoparticles from the medicine, agricultural field to the environmental bioremediation.

The medical properties of metals have been explored for centuries in traditional medicine for the treatment of infections and diseases and still practiced to date. Platinum-based drugs are the first class of metal-based drugs to be clinically used as anticancer agents following the approval of cisplatin by the United States Food and Drug Administration (FDA) over 40 years ago. Since then, more metals with health benefits have been approved for clinical trials. Interestingly, when these metals are reduced to metallic nanoparticles, they displayed unique and novel properties that were superior to their bulk counterparts. Gold nanoparticles (AuNPs) are among the FDA-approved metallic nanoparticles and have shown great promise in a variety of roles in medicine. They were used as drug delivery, photothermal (PT), contrast, therapeutic, radiosensitizing, and gene transfection agents. Their biomedical applications are reviewed herein, covering their potential use in disease diagnosis and therapy. Some of the AuNP-based systems that are approved for clinical trials are also discussed, as well as the potential health threats of AuNPs and some strategies that can be used to improve their biocompatibility. The reviewed studies offer proof of principle that AuNP-based systems could potentially be used alone or in combination with the conventional systems to improve their efficacy.

Adherent cells are highly sensitive to the physical and biochemical properties of their microenvironment, particularly the extracellular matrix (ECM), which regulates cell adhesion, signaling, and overall behavior. Cells also actively modify and remodel the ECM, creating a continuous interaction comparable to a dialogue. Consequently, artificial cell microenvironments are used to influence adherent cell behavior. However, these environments must be carefully modulated to enhance communication with cells. To this end, bio‐functionalization of cell culture substrates has been developed to improve interactions between adherent cells and their microenvironment. To optimize cell–biomaterial surface interactions, various protein grafting techniques can be employed, including random grafting via amine groups, semi‐oriented grafting via thiol groups, and glycosylation‐based grafting. This study specifically focuses on the glycosylation‐based grafting method, which creates a natural spacer between the substrate and the immobilized protein. We introduce a novel glycan‐based surface functionalization approach using two ECM adhesion proteins commonly used in biomaterials: fibronectin (Fn), a fibrillar protein with low glycosylation (5% w/w), and vitronectin (Vn), a globular protein with high glycosylation (30% w/w). Both proteins are highly purified from human blood plasma to preserve their native state and bioactivity. We analyzed the effects of glycan‐based grafting on the conformation and bioactivity of these proteins. Given their essential roles in ECM, human pre‐osteoblastic STRO‐1⁺A cells are cultured on the bio‐functionalized surfaces, and their early‐stage behavior is compared for both Fn and Vn. Our results demonstrate that glycosylation‐based grafting significantly influences the conformation and bioactivity of Fn and Vn. Cell adhesion, viability, and morphology are assessed, revealing that this grafting method enhances cell–material interactions, making it a promising strategy for improving the performance of biomaterials in biomedical applications. We present a glycan‐mediated strategy for covalent grafting of extracellular matrix proteins onto polystyrene surfaces. This approach preserves protein bioactivity and enhances cell adhesion and viability. Using fibronectin and vitronectin, we demonstrate stable immobilization via glycosylation sites, offering a promising route for advanced biofunctionalization of biomaterials.

The continuous improvement of the technical potential of bioelectronic devices for biosensing applications will provide clinicians with a reliable tool for biomarker quantification down to the single molecule. Eventually, physicians will be able to identify the very moment at which the illness state begins, with a terrific impact on the quality of life along with a reduction of health care expenses. However, in clinical practice, to gather enough information to formulate a diagnosis, multiple biomarkers are normally quantified from the same biological sample simultaneously. Therefore, it is critically important to translate lab-based bioelectronic devices based on electrolyte gated thin-film transistor technology into a cost-effective portable multiplexing array prototype. In this perspective, the assessment of cost-effective manufacturability represents a crucial step, with specific regard to the optimization of the bio-functionalization protocol of the transistor gate module. Hence, we have assessed, using surface plasmon resonance technique, a sustainable and reliable cost-effective process to successfully bio-functionalize a gold surface, suitable as gate electrode for wide-field bioelectronic sensors. The bio-functionalization process herein investigated allows to reduce the biorecognition element concentration to one-tenth, drastically impacting the manufacturing costs while retaining high analytical performance.

The lack of bioactivity in three-dimensional (3D)-printing of poly-є-caprolactone (PCL) scaffolds limits cell-material interactions in bone tissue engineering. This constraint can be overcome by surface-functionalization using glycosaminoglycan-like anionic polysaccharides, e.g., carboxymethyl cellulose (CMC), a plant-based carboxymethylated, unsulfated polysaccharide, and κ-carrageenan, a seaweed-derived sulfated, non-carboxymethylated polysaccharide. The sulfation of CMC and carboxymethylation of κ-carrageenan critically improve their bioactivity. However, whether sulfated carboxymethyl cellulose (SCMC) and carboxymethyl κ-carrageenan (CM-κ-Car) affect the osteogenic differentiation potential of pre-osteoblasts on 3D-scaffolds is still unknown. Here, we aimed to assess the effects of surface-functionalization by SCMC or CM-κ-Car on the physicochemical and mechanical properties of 3D-printed PCL scaffolds, as well as the osteogenic response of pre-osteoblasts. MC3T3-E1 pre-osteoblasts were seeded on 3D-printed PCL scaffolds that were functionalized by CM-κ-Car (PCL/CM-κ-Car) or SCMC (PCL/SCMC), cultured up to 28 days. The scaffolds’ physicochemical and mechanical properties and pre-osteoblast function were assessed experimentally and by finite element (FE) modeling. We found that the surface-functionalization by SCMC and CM-κ-Car did not change the scaffold geometry and structure but decreased the elastic modulus. Furthermore, the scaffold surface roughness and hardness increased and the scaffold became more hydrophilic. The FE modeling results implied resilience up to 2% compression strain, which was below the yield stress for all scaffolds. Surface-functionalization by SCMC decreased Runx2 and Dmp1 expression, while surface-functionalization by CM-κ-Car increased Cox2 expression at day 1. Surface-functionalization by SCMC most strongly enhanced pre-osteoblast proliferation and collagen production, while CM-κ-Car most significantly increased alkaline phosphatase activity and mineralization after 28 days. In conclusion, surface-functionalization by SCMC or CM-κ-Car of 3D-printed PCL-scaffolds enhanced pre-osteoblast proliferation and osteogenic activity, likely due to increased surface roughness and hydrophilicity. Surface-functionalization by SCMC most strongly enhanced cell proliferation, while CM-κ-Car most significantly promoted osteogenic activity, suggesting that surface-functionalization by CM-κ-Car may be more promising, especially in the short-term, for in vivo bone formation.

Fused filament fabrication (FFF) enables patient-specific scaffolds for critical-size bone defects, but most filaments are bioinert and difficult to functionalize at high particulate loadings due to segregation, agglomeration, clogging, and diameter instability. We developed a mechanism-guided extrusion toolkit to stabilize polylactic acid (PLA) filaments containing human demineralized bone matrix (DBM) or cortical granulate (CG) up to 70 wt%. PLA was ground, dried, silicone pre-coated, and compounded with DBM or CG (25/40/70 wt%) using starve-fed extrusion, sequential extrusion, and post-die mixing to maintain stable diameters. FFF produced disks and tubes. MSC adhesion was assessed by SEM. qPCR (control vs. osteogenic medium) quantified RUNX2, ALP, BGLAP, COL1A, VEGF, IL-6, MAPK8. Tubes underwent three-point bending. The toolkit yielded printable, dimensionally stable filaments at 25–70 wt% with uniform dispersion and surface-exposed filler. Both composites increased early mesenchymal stromal cells (MSC) adhesion versus PLA. RUNX2 was increased on DBM40 versus PLA. VEGF was elevated on CG25 (DBM40 trend). Under osteogenic medium, IL-6 and MAPK8 were generally reduced. Mechanics were loading-dependent: CG25 exceeded CG70 and DBM25, while DBM40/70 recovered stiffness versus DBM25. A mechanism-guided extrusion toolkit enables high-loading PLA–DBM/CG filaments with excellent printability and material-specific biological and mechanical advantages over PLA.

Titanium (Ti) and titanium alloy have been widely used in orthopedics. However, the successful application of titanium implants is mainly limited due to implant-associated infections. The implant surface contributes to osseointegration, but also has the risk of accelerating the growth of bacterial colonies, and the implant surfaces infected with bacteria easily form biofilms that are resistant to antibiotics. Biofilm-related implant infections are a disastrous complication of trauma orthopedic surgery and occur when an implant is colonized by bacteria. Surface bio-functionalization has been extensively studied to better realize the inhibition of bacterial proliferation to further optimize the mechanical functions of implants. Recently, the surface bio-functionalization of titanium implants has been presented to improve osseointegration. However, there are still numerous clinical and non-clinical challenges. In this review, these aspects were highlighted to develop surface bio-functionalization strategies for enhancing the clinical application of titanium implants to eliminate implant-associated infections.

Biocompatibility, flexibility and durability make polydimethylsiloxane (PDMS) membranes top candidates in biomedical applications. CellDrum technology uses large area, <10 µm thin membranes as mechanical stress sensors of thin cell layers. For this to be successful, the properties (thickness, temperature, dust, wrinkles, etc.) must be precisely controlled. The following parameters of membrane fabrication by means of the Floating-on-Water (FoW) method were investigated: (1) PDMS volume, (2) ambient temperature, (3) membrane deflection and (4) membrane mechanical compliance. Significant differences were found between all PDMS volumes and thicknesses tested (p < 0.01). They also differed from the calculated values. At room temperatures between 22 and 26 °C, significant differences in average thickness values were found, as well as a continuous decrease in thicknesses within a 4 °C temperature elevation. No correlation was found between the membrane thickness groups (between 3–4 µm) in terms of deflection and compliance. We successfully present a fabrication method for thin bio-functionalized membranes in conjunction with a four-step quality management system. The results highlight the importance of tight regulation of production parameters through quality control. The use of membranes described here could also become the basis for material testing on thin, viscous layers such as polymers, dyes and adhesives, which goes far beyond biological applications.

Metallic nanoparticles are considered as active supports in the development of specific chemical or biological biosensors. Well-organized nanoparticles can be prepared either through expensive (e.g., electron beam lithography) or inexpensive (e.g., thermal synthesis) approaches where different shapes of nanoparticles are easily obtained over large solid surfaces. Herein, the authors propose a low-cost thermal synthesis of active plasmonic nanostructures on thin gold layers modified glass supports after 1 h holding on a hot plate (~350 °C). The resulted annealed nanoparticles proved a good reproducibility of localized surface plasmon resonance (LSPR) and surface enhanced Raman spectroscopy (SERS) optical responses and where used for the detection of low concentrations of two model (bio)chemical molecules, namely the human cytochrome b5 (Cyt-b5) and trans-1,2-bis(4-pyridyl)ethylene (BPE).