Metal-based nanoparticles for bone tissue engineering

Nanotechnology in tissue engineering: expanding possibilities with nanoparticles

Tissue engineering is a multidisciplinary field that merges engineering, material science, and medical biology in order to develop biological alternatives for repairing, replacing, maintaining, or boosting the functionality of tissues and organs. The ultimate goal of tissue engineering is to create biological alternatives for repairing, replacing, maintaining, or enhancing the functionality of tissues and organs. However, the current landscape of tissue engineering techniques presents several challenges, including a lack of suitable biomaterials, inadequate cell proliferation, limited methodologies for replicating desired physiological structures, and the unstable and insufficient production of growth factors, which are essential for facilitating cell communication and the appropriate cellular responses. Despite these challenges, there has been significant progress made in tissue engineering techniques in recent years. Nanoparticles hold a major role within the realm of nanotechnology due to their unique qualities that change with size. These particles, which provide potential solutions to the issues that are met in tissue engineering, have helped propel nanotechnology to its current state of prominence. Despite substantial breakthroughs in the utilization of nanoparticles over the past two decades, the full range of their potential in addressing the difficulties within tissue engineering remains largely untapped. This is due to the fact that these advancements have occurred in relatively isolated pockets. In the realm of tissue engineering, the purpose of this research is to conduct an in-depth investigation of the several ways in which various types of nanoparticles might be put to use. In addition to this, it sheds light on the challenges that need to be conquered in order to unlock the maximum potential of nanotechnology in this area.

Nanomaterials in the environment and their pragmatic voyage at various trophic levels in an ecosystem

In the development of nanotechnology, nanomaterials (NMs) have a huge credential in advancing the existing follow-ups of analytical and diagnosis techniques, drug designing, agricultural science, electronics, cosmetics, sports, textiles and water purification. However, NMs have also grasped attention of researchers onto their toxicity. In the present review, initially the development of notable NMs such as metal and metal-oxide nanoparticles (NPs), magnetic NPs, carbon-based NMs and quantum dots intended to be commercialized along with their applications are discussed. This is followed by the current scenario of NMs in the environment to widen the outlook on the concentration of NPs in the environmental compartments and the frequency of organism exposed to NPs at varied trophic levels. In order to understand the physiochemical and morphological significance of NPs in exhibiting toxicity, fate of NPs in the environment is briefly deliberated. This is further geared-up to glance in-sightedly on the organisms starting from primary producer to primary consumer, secondary consumer, tertiary consumer and decomposers encountering NPs in their habitual niche. The state of NPs to which organisms are exposed, mechanism of NP uptake and toxicity, anomalies faced at each trophic level, concentration of NPs that is liable to cause toxicity and, biotransfer of NPs to the next generation and trophic level are detailed. Finally, the future prospects on bioaccumulation and biomagnification of NP-based products are conversed. Thus, the review would be noteworthy in unveiling the significance of NPs in forthcoming years combined with threat towards each organism in an ecosystem.

Facile fabrication of linezolid/strontium coated hydroxyapatite/graphene oxide nanocomposite for osteoporotic bone defect

Hydroxyapatite (HAp) coatings currently have limited therapeutic applications because they lack anti-infection, osteoinductivity, and poor mechanical characteristics. On the titanium substrate, electrochemical deposition (ECD) was used to construct the strontium (Sr)-featuring hydroxyapatite (HAp)/graphene oxides (GO)/linezolid (LZ) nanomaterial coated with antibacterial and drug delivery properties. The newly fabricated nanomaterials were confirmed by X-ray diffraction analysis (XRD), Fourier-transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) analysis and morphological features were examined by scanning electron microscope (SEM) analysis. The results reveal multiple nucleation sites for SrHAp/GO/LZ composite coatings due to oxygen-comprising moieties on the 2D surface of GO. It was shown to be favorable for osteoblast proliferation and differentiation. The elastic modulus and hardness of LZ nanocomposite with SrHAp/GO/LZ coatings were increased by 67 % and 121 %, respectively. An initial 5 h burst of LZ release from the SrHAp/GO/LZ coating was followed by 14 h of gradual release, owing to LZ's physical and chemical adsorption. The SrHAp/GO/LZ coating effectively inhibited both S. epidermidis and S. aureus, and the inhibition lasted for three days, as demonstrated by the inhibition zone and colony count assays. When MG-63 cells are coated with SrHAp/GO/LZ composite coating, their adhesion, proliferation, and differentiation greatly improve when coated with pure titanium. A novel surface engineering nanomaterial for treating and preventing osteoporotic bone defects, SrHAp/GO/LZ, was shown to have high mechanical characteristics, superior antibacterial abilities, and osteoinductivity.

Recent advances on biomedical applications of gellan gum: A review

Gellan gum (GG) has attracted considerable attention as a versatile biopolymer with numerous potential biological applications, especially in the fields of tissue engineering, wound healing, and cargo delivery. Due to its distinctive characteristics like biocompatibility, biodegradability, nontoxicity, and gel-forming ability, GG is well-suited for these applications. This review focuses on recent research on GG-based hydrogels and biocomposites and their biomedical applications. It discusses the incorporation of GG into hydrogels for controlled drug release, its role in promoting wound healing processes, and its potential in tissue engineering for various tissues including bone, retina, cartilage, vascular, adipose, and cardiac tissue. It provides an in-depth analysis of the latest findings and advancements in these areas, making it a valuable resource for researchers and professionals in these fields.

Biochemical Behavior, Influence on Cell DNA Condition, and Microbiological Properties of Wool and Wool-Copper Materials

The paper presents the study concerning the preparation and physio-chemical and biological properties of wool-copper (WO-Cu) materials obtained by the sputter deposition of copper onto the wool fibers. The WO-Cu material was subjected to physio-chemical and biological investigations. The physio-chemical investigations included the elemental analysis of materials (C, N, O, S, and Cu), their microscopic analysis, and surface properties analysis (specific surface area and total pore volume). The biological investigations consisted of the antimicrobial activity tests of the WO-Cu materials against colonies of Gram-positive (Staphylococcus aureus) bacteria, Gram-negative (Escherichia coli) bacteria, and fungal mold species (Chaetomium globosum). Biochemical-hematological tests included the evaluation of the activated partial thromboplastin time and pro-thrombin time. The tested wool-copper demonstrated the ability to interact with the DNA in a time-dependent manner. These interactions led to the DNA's breaking and degradation. The antimicrobial and antifungal activities of the WO-Cu materials suggest a potential application as an antibacterial/antifungal material. Wool-copper materials may be also used as customized materials where the blood coagulation process could be well controlled through the appropriate copper content.

Pioneering nanomedicine in orthopedic treatment care: a review of current research and practices

A developing use of nanotechnology in medicine involves using nanoparticles to administer drugs, genes, biologicals, or other materials to targeted cell types, such as cancer cells. In healthcare, nanotechnology has brought about revolutionary changes in the treatment of various medical and surgical conditions, including in orthopedic. Its clinical applications in surgery range from developing surgical instruments and suture materials to enhancing imaging techniques, targeted drug delivery, visualization methods, and wound healing procedures. Notably, nanotechnology plays a significant role in preventing, diagnosing, and treating orthopedic disorders, which is crucial for patients' functional rehabilitation. The integration of nanotechnology improves standards of patient care, fuels research endeavors, facilitates clinical trials, and eventually improves the patient's quality of life. Looking ahead, nanotechnology holds promise for achieving sustained success in numerous surgical disciplines, including orthopedic surgery, in the years to come. This review aims to focus on the application of nanotechnology in orthopedic surgery, highlighting the recent development and future perspective to bridge the bridge for clinical translation.

Potential Biomedical Applications of Terbium-Based Nanoparticles (TbNPs): A Review on Recent Advancement

The scientific world is increasingly focusing on rare earth metal oxide nanomaterials due to their consequential biological prospects, navigated by breakthroughs in biomedical applications. Terbium belongs to rare earth elements (lanthanide series) and possesses remarkably strong luminescence at lower energy emission and signal transduction properties, ushering in wide applications for diagnostic measurements (i.e., bioimaging, biosensors, fluorescence imaging, etc.) in the biomedical sectors. In addition, the theranostic applications of terbium-based nanoparticles further permit the targeted delivery of drugs to the specific site of the disease. Furthermore, the antimicrobial properties of terbium nanoparticles induced via reactive oxygen species (ROS) cause oxidative damage to the cell membrane and nuclei of living organisms, ion release, and surface charge interaction, thus further creating or exhibiting excellent antioxidant characteristics. Moreover, the recent applications of terbium nanoparticles in tissue engineering, wound healing, anticancer activity, etc., due to angiogenesis, cell proliferation, promotion of growth factors, biocompatibility, cytotoxicity mitigation, and anti-inflammatory potentials, make this nanoparticle anticipate a future epoch of nanomaterials. Terbium nanoparticles stand as a game changer in the realm of biomedical research, proffering a wide array of possibilities, from revolutionary imaging techniques to advanced drug delivery systems. Their unique properties, including luminescence, magnetic characteristics, and biocompatibility, have redefined the boundaries of what can be achieved in biomedicine. This review primarily delves into various mechanisms involved in biomedical applications via terbium-based nanoparticles due to their physicochemical characteristics. This review article further explains the potential biomedical applications of terbium nanoparticles with in-depth significant mechanisms from the individual literature. This review additionally stands as the first instance to furnish a "single-platted" comprehensive acquaintance of terbium nanoparticles in shaping the future of healthcare as well as potential limitations and overcoming strategies that require exploration before being trialed in clinical settings.

Low-Temperature Deposited Amorphous Poly(aryl ether ketone) Hierarchically Porous Scaffolds with Strontium-Doped Mineralized Coating for Bone Defect Repair

In recent years, the demand for clinical bone grafting has increased. As a new solution for orthopedic implants, polyether ether ketone (PEEK, crystalline PAEK) has excellent comprehensive performance and is practically applied in the clinic. In this research, a noteworthy elevated scheme to enhance the performance of PEEK scaffolds is presented. The amorphous aggregated poly (aryl ether ketone) (PAEK) resin is prepared as the matrix material, which maintains high mechanical strength and can be processed through the solution. So, the tissue engineering scaffolds with multilevel pores can be printed by low-temperature deposited manufacturing (LDM) to improve biologically inert scaffolds with smooth surfaces. Also, the feature of PAEK's solution processing is profitable to uniformly add the functional components for bone repair. Ultimately, A system of orthopedic implantable PAEK material based on intermolecular interactions, surface topology, and surface modification is established. The specific steps include synthesizing PAEK that contain polar carboxyl structures, preparing bioinks and fabricating scaffolds by LDM, preparation of scaffolds with strontium-doped mineralized coatings, evaluation of their osteogenic properties in vitro and in vivo, and investigation on the effect and mechanism of scaffolds in promoting osteogenic differentiation. This work provides an upgraded system of PAEK implantable materials for clinical application.

3D printing technology and its combination with nanotechnology in bone tissue engineering

With the graying of the world's population, the morbidity of age-related chronic degenerative bone diseases, such as osteoporosis and osteoarthritis, is increasing yearly, leading to an increased risk of bone defects, while current treatment methods face many problems, such as shortage of grafts and an incomplete repair. Therefore, bone tissue engineering offers an alternative solution for regenerating and repairing bone tissues by constructing bioactive scaffolds with porous structures that provide mechanical support to damaged bone tissue while promoting angiogenesis and cell adhesion, proliferation, and activity. 3D printing technology has become the primary scaffold manufacturing method due to its ability to precisely control the internal pore structure and complex spatial shape of bone scaffolds. In contrast, the fast development of nanotechnology has provided more possibilities for the internal structure and biological function of scaffolds. This review focuses on the application of 3D printing technology in bone tissue engineering and nanotechnology in the field of bone tissue regeneration and repair, and explores the prospects for the integration of the two technologies.

Leveraging the Recent Advancements in GelMA Scaffolds for Bone Tissue Engineering: An Assessment of Challenges and Opportunities

The field of bone tissue engineering has seen significant advancements in recent years. Each year, over two million bone transplants are performed globally, and conventional treatments, such as bone grafts and metallic implants, have their limitations. Tissue engineering offers a new level of treatment, allowing for the creation of living tissue within a biomaterial framework. Recent advances in biomaterials have provided innovative approaches to rebuilding bone tissue function after damage. Among them, gelatin methacryloyl (GelMA) hydrogel is emerging as a promising biomaterial for supporting cell proliferation and tissue regeneration, and GelMA has exhibited exceptional physicochemical and biological properties, making it a viable option for clinical translation. Various methods and classes of additives have been used in the application of GelMA for bone regeneration, with the incorporation of nanofillers or other polymers enhancing its resilience and functional performance. Despite promising results, the fabrication of complex structures that mimic the bone architecture and the provision of balanced physical properties for both cell and vasculature growth and proper stiffness for load bearing remain as challenges. In terms of utilizing osteogenic additives, the priority should be on versatile components that promote angiogenesis and osteogenesis while reinforcing the structure for bone tissue engineering applications. This review focuses on recent efforts and advantages of GelMA-based composite biomaterials for bone tissue engineering, covering the literature from the last five years.

Bone Tissue Engineering and Nanotechnology: A Promising Combination for Bone Regeneration

Large bone defects are the leading contributor to disability worldwide, affecting approximately 1.71 billion people. Conventional bone graft treatments show several disadvantages that negatively impact their therapeutic outcomes and limit their clinical practice. Therefore, much effort has been made to devise new and more effective approaches. In this context, bone tissue engineering (BTE), involving the use of biomaterials which are able to mimic the natural architecture of bone, has emerged as a key strategy for the regeneration of large defects. However, although different types of biomaterials for bone regeneration have been developed and investigated, to date, none of them has been able to completely fulfill the requirements of an ideal implantable material. In this context, in recent years, the field of nanotechnology and the application of nanomaterials to regenerative medicine have gained significant attention from researchers. Nanotechnology has revolutionized the BTE field due to the possibility of generating nanoengineered particles that are able to overcome the current limitations in regenerative strategies, including reduced cell proliferation and differentiation, the inadequate mechanical strength of biomaterials, and poor production of extrinsic factors which are necessary for efficient osteogenesis. In this review, we report on the latest in vitro and in vivo studies on the impact of nanotechnology in the field of BTE, focusing on the effects of nanoparticles on the properties of cells and the use of biomaterials for bone regeneration.

3D printed arrowroot starch-gellan scaffolds for wound healing applications

Skin, the largest organ in the body, blocks the entry of environmental pollutants into the system. Any injury to this organ allows infections and other harmful substances into the body. 3D bioprinting, a state-of-the-art technique, is suitable for fabricating cell culture scaffolds to heal chronic wounds rapidly. This study uses starch extracted from Maranta arundinacea (Arrowroot plant) (AS) and gellan gum (GG) to develop a bioink for 3D printing a scaffold capable of hosting animal cells. Field emission scanning electron microscopy (FE-SEM) and X-ray diffraction analysis (XRD) prove that the isolated AS is analogous to commercial starch. The cell culture scaffolds developed are superior to the existing monolayer culture. Infrared microscopy shows the AS-GG interaction and elucidates the mechanism of hydrogel formation. The physicochemical properties of the 3D-printed scaffold are analyzed to check the cell adhesion and growth; SEM images have confirmed that the AS-GG printed scaffold can support cell growth and proliferation, and the MTT assay shows good cell viability. Cell behavioral and migration studies reveal that cells are healthy. Since the scaffold is biocompatible, it can be 3D printed to any shape and structure and will biodegrade in the requisite time.

Modulation of calcium-influx by carboxymethyl tamarind‑gold nanoparticles promotes biomineralization for tissue regeneration

Gold nanoparticles (AuNPs) have been reported to modulate bone tissue regeneration and are being extensively utilized in biomedical implementations attributable to their low cytotoxicity, biocompatibility and simplicity of functionalization. Lately, biologically synthesized nanoparticles have acquired popularity because of their environmentally acceptable alternatives for diverse applications. Here we report the green synthesis of AuNPs by taking the biopolymer Carboxymethyl Tamarind (CMT) as a unique reducing as well as a stabilizing agent. The synthesized CMT-AuNPs were analyzed by UV-vis spectrophotometer, DLS, FTIR, XRD, TGA, SEM and TEM. These results suggest that CMT-AuNPs possess an average size of 19.93 ± 8.52 nm and have long-term stability. Further, these CMT-AuNPs promote the proliferation together with the differentiation and mineralization of osteoblast cells in a "dose-dependent" manner. Additionally, CMT-AuNPs are non-toxic to SD rats when applied externally. We suggest that the CMT-AuNPs have the potential to be a suitable and non-toxic agent for differentiation and mineralization of osteoblast cells in vitro and this can be tested in vivo as well.

Investigation of background, novelty and recent advance of iron (II,III) oxide- loaded on 3D polymer based scaffolds as regenerative implant for bone tissue engineering: A review

Bone tissue engineering had crucial role in the bone defects regeneration, particularly when allograft and autograft procedures have limitations. In this regard, different types of scaffolds are used in tissue regeneration as fundamental tools. In recent years, magnetic scaffolds show promising applications in different biomedical applications (in vitro and in vivo). As superparamagnetic materials are widely considered to be among the most attractive biomaterials in tissue engineering, due to long-range stability and superior bioactivity, therefore, magnetic implants shows angiogenesis, osteoconduction, and osteoinduction features when they are combined with biomaterials. Furthermore, these scaffolds can be coupled with a magnetic field to enhance their regenerative potential. In addition, magnetic scaffolds can be composed of various combinations of magnetic biomaterials and polymers using different methods to improve the magnetic, biocompatibility, thermal, and mechanical properties of the scaffolds. This review article aims to explain the use of magnetic biomaterials such as iron (II,III) oxide (Fe2O3 and Fe3O4) in detail. So it will cover the research background of magnetic scaffolds, the novelty of using these magnetic implants in tissue engineering, and provides a future perspective on regenerative implants.

Emerging Trends in Zinc Ferrite Nanoparticles for Biomedical and Environmental Applications

Over the last few decades, the application of nanoparticles (NPs) gained immense attention towards environmental and biomedical applications. NPs are ultra-small particles having size ranges from 1 to 100 nm. NPs loaded with therapeutic or imaging compounds have proved a versatile approach towards healthcare improvements. Among various inorganic NPs, zinc ferrite (ZnFe2O4) NPs are considered as non-toxic and having an improved drug delivery characteristics . Several studies have reported broader applications of ZnFe2O4 NPs for treating carcinoma and various infectious diseases. Additionally, these NPs are beneficial for reducing organic and inorganic environmental pollutants. This review discusses about various methods to fabricate ZnFe2O4 NPs and their physicochemical properties. Further, their biomedical and environmental applications have also been explored comprehensively.

Recent progress and treatment strategy of pectin polysaccharide based tissue engineering scaffolds in cancer therapy, wound healing and cartilage regeneration

Natural polymers and its mixtures in the form of films, sponges and hydrogels are playing a major role in tissue engineering and regenerative medicine. Hydrogels have been extensively investigated as standalone materials for drug delivery purposes as they enable effective encapsulation and sustained release of drugs. Biopolymers are widely utilised in the fabrication of hydrogels due to their safety, biocompatibility, low toxicity, and regulated breakdown by human enzymes. Among all the biopolymers, polysaccharide-based polymer is well suited to overcome the limitations of traditional wound dressing materials. Pectin is a polysaccharide which can be extracted from different plant sources and is used in various pharmaceutical and biomedical applications including cartilage regeneration. Pectin itself cannot be employed as scaffolds for tissue engineering since it decomposes quickly. This article discusses recent research and developments on pectin polysaccharide, including its types, origins, applications, and potential demands for use in AI-mediated scaffolds. It also covers the materials-design process, strategy for implementation to material selection and fabrication methods for evaluation. Finally, we discuss unmet requirements and current obstacles in the development of optimal materials for wound healing and bone-tissue regeneration, as well as emerging strategies in the field.

Plant molecules reinforce bone repair: Novel insights into phenol-modified bone tissue engineering scaffolds for the treatment of bone defects

Bone defects have become a major cause of disability and death. To overcome the limitations of natural bone implants, including donor shortages and immune rejection risks, bone tissue engineering (BTE) scaffolds have emerged as a promising therapy for bone defects. Despite possessing good biocompatibility, these metal, ceramic and polymer-based scaffolds are still challenged by the harsh conditions in bone defect sites. ROS accumulation, bacterial infection, excessive inflammation, compromised blood supply deficiency and tumor recurrence negatively impact bone tissue cells (BTCs) and hinder the osteointegration of BTE scaffolds. Phenolic compounds, derived from plants and fruits, have gained growing application in treating inflammatory, infectious and aging-related diseases due to their antioxidant ability conferred by phenolic hydroxyl groups. The prevalent interactions between phenols and functional groups also facilitate their utilization in fabricating scaffolds. Consequently, phenols are increasingly incorporated into BTE scaffolds to boost therapeutic efficacy in bone defect. This review demonstrated the effects of phenols on BTCs and bone defect microenvironment, summarized the intrinsic mechanisms, presented the advances in phenol-modified BTE scaffolds and analyzed their potential risks in practical applications. Overall, phenol-modified BTE scaffolds hold great potential for repairing bone defects, offering novel patterns for BTE scaffold construction and advancing traumatological medicine.

Experimental Verification of the Impact of the Contact Area between the Defect Site and the Scaffold on Bone Regeneration Efficacy

In the field of bone tissue engineering, which is being developed for the ideal restoration of bone defects, researchers are exploring the improvement of the bone regeneration efficacy of scaffolds through various approaches involving osteoconductive, osteoinductive, and angiogenic factors. In the current trend of research, there is also a suggestion that the topological factors of recent scaffolds may influence the attachment, migration, proliferation, and differentiation of bone cells. Building upon experimental confirmation of the effect of scaffold conformity with the defect site on enhanced bone regeneration in previous studies, we conducted this research to experimentally investigate the relationship between contact area with the defect site and bone regeneration efficacy. The results demonstrated that as the contact area of the scaffold increased, not only did the resistance to bone tissue growth increase, more significant bone regeneration also occurred, as evidenced through histological analysis and micro-CT analysis. This research confirms that the contact area between the scaffold and the defect site is a critical variable affecting bone regeneration efficacy, emphasizing its importance when designing customized scaffolds. This finding holds promising implications for future studies and applications in the field.

Effects of mechanical properties of carbon-based nanocomposites on scaffolds for tissue engineering applications: a comprehensive review

Mechanical properties, such as elasticity modulus, tensile strength, elongation, hardness, density, creep, toughness, brittleness, durability, stiffness, creep rupture, corrosion and wear, a low coefficient of thermal expansion, and fatigue limit, are some of the most important features of a biomaterial in tissue engineering applications. Furthermore, the scaffolds used in tissue engineering must exhibit mechanical and biological behaviour close to the target tissue. Thus, a variety of materials has been studied for enhancing the mechanical performance of composites. Carbon-based nanostructures, such as graphene oxide (GO), reduced graphene oxide (rGO), carbon nanotubes (CNTs), fibrous carbon nanostructures, and nanodiamonds (NDs), have shown great potential for this purpose. This is owing to their biocompatibility, high chemical and physical stability, ease of functionalization, and numerous surface functional groups with the capability to form covalent bonds and electrostatic interactions with other components in the composite, thus significantly enhancing their mechanical properties. Considering the outstanding capabilities of carbon nanostructures in enhancing the mechanical properties of biocomposites and increasing their applicability in tissue engineering and the lack of comprehensive studies on their biosafety and role in increasing the mechanical behaviour of scaffolds, a comprehensive review on carbon nanostructures is provided in this study.

Magnetic xanthan gum-silk fibroin hydrogel: A nanocomposite for biological and hyperthermia applications

A magnetic xanthan hydrogel/silk fibroin nanobiocomposite (XG hydrogel/SF/Fe3O4) was designed, fabricated, and characterized using analyzing methods such as FT-IR, EDX, FE-SEM, XRD, TGA, and VSM to evaluate the exact structure of product nanobiocomposite. The FE-SEM images reveal the presence of spherical shapes exhibiting a narrow size range and homogeneous distribution, measuring between 30 and 35 nm in diameter. The VSM analysis demonstrates the superparamagnetic properties of the XG hydrogel/SF/Fe3O4 nanobiocomposite, exhibiting a magnetic saturation of 54 emu/g at room temperature. The biological response of the nanobiocomposite scaffolds was assessed through cell viability and red blood cell hemolytic assays. MCF10A cells were exposed to a concentration of 1.75 mg/mL of the nanobiocomposite, and after 2 and 3 days, the cell viability was found to be 96.95 % and 97.02 %, respectively. The hemolytic effect was nearly 0 % even at higher concentrations (2 mg/mL). Furthermore, the magnetic nanobiocomposite showed excellent potential for hyperthermia applications, with a maximum specific absorption rate of 7 W/g for 1 mg/mL of the sample under a magnetic field in different frequencies (100, 200, 300, and 400 MHz) and 5 to 20 min time intervals.

Magnetically-actuated microcages for cells entrapment, fabricated by laser direct writing via two photon polymerization

The manipulation of biological materials at cellular level constitutes a sine qua non and provocative research area regarding the development of micro/nano-medicine. In this study, we report on 3D superparamagnetic microcage-like structures that, in conjunction with an externally applied static magnetic field, were highly efficient in entrapping cells. The microcage-like structures were fabricated using Laser Direct Writing via Two-Photon Polymerization (LDW via TPP) of IP-L780 biocompatible photopolymer/iron oxide superparamagnetic nanoparticles (MNPs) composite. The unique properties of LDW via TPP technique enabled the reproduction of the complex architecture of the 3D structures, with a very high accuracy i.e., about 90 nm lateral resolution. 3D hyperspectral microscopy was employed to investigate the structural and compositional characteristics of the microcage-like structures. Scanning Electron Microscopy coupled with Energy Dispersive X-Ray Spectroscopy was used to prove the unique features regarding the morphology and the functionality of the 3D structures seeded with MG-63 osteoblast-like cells. Comparative studies were made on microcage-like structures made of IP-L780 photopolymer alone (i.e., without superparamagnetic properties). We found that the cell-seeded structures made by IP-L780/MNPs composite actuated by static magnetic fields of 1.3 T were 13.66 ± 5.11 folds (p < 0.01) more efficient in terms of cells entrapment than the structures made by IP-L780 photopolymer alone (i.e., that could not be actuated magnetically). The unique 3D architecture of the microcage-like superparamagnetic structures and their actuation by external static magnetic fields acted in synergy for entrapping osteoblast-like cells, showing a significant potential for bone tissue engineering applications.

Casein-assisted exfoliation of tungsten disulfide nanosheets for biomedical applications

Our regular life can be more challenging by bone abnormalities. Bone tissue engineering is used for repairing, regenerating, or replacing bone tissue that has been injured or infected. It is effective in overcoming the drawbacks of conventional bone grafting methods like autograft and allograft by enhancing the effectiveness of bone regeneration. Recent discoveries have shown that the exfoliation of transition metal dichalcogenides (TMDs) with protein is in great demand for bone tissue engineering applications. WS2 nanosheets were developed using casein and subsequently characterized with different analytical techniques. Strong absorption peaks were observed in the UV-visible spectra at 520 nm and 630 nm. Alginate and alginate-casein WS2 microspheres were developed. Stereomicroscopic images of the microspheres are spherical in shape and have an average diameter of around 0.8 ± 0.2 mm. The alginate-casein WS2 microspheres show higher content of water absorption and retention properties than only alginate-containing microspheres. The apatite formation in the simulated bodily fluid solution was facilitated more effectively by the alginate-casein-WS2 microspheres. Additionally, alginate-casein-WS2 microspheres have a compressive strength is 58.01 ± 4 MPa. Finally, in vitro cell interaction studies reveals that both the microspheres are biocompatible with the C3H10T1/2 cells, and alginate-casein-WS2-based microspheres promote cell growth more significantly. Alginate-casein-WS2 microspheres promote alkaline phosphatase activity, and mineralization process. Additionally, alginate-casein-WS2-based microspheres exponentially enhance the genes for ALP, BMP-2, OCN, and Collage type-1. The produced alginate-casein-WS2 microspheres could be a suitable synthetic graft for a bone transplant replacement.

Nanomaterial-based drug delivery of immunomodulatory factors for bone and cartilage tissue engineering

As life expectancy continues to increase, so do disorders related to the musculoskeletal system. Orthopedics-related impairments remain a challenge, with nearly 325 thousand and 120 thousand deaths recorded in 2019. Musculoskeletal system, including bone and cartilage tissue, is a living system in which cells constantly interact with the immune system, which plays a key role in the tissue repair process. An alternative to bridge the gap between these two systems is exploiting nanomaterials, as they have proven to serve as delivery agents of an array of molecules, including immunomodulatory agents (anti-inflammatory drugs, cytokines), as well as having the ability to mimic tissue by their nanoscopic structure and promote tissue repair per se. Therefore, this review outlooks nanomaterials and immunomodulatory factors widely employed in the area of bone and cartilage tissue engineering. Emerging developments in nanomaterials for delivery of immunomodulatory agents for bone and cartilage tissue engineering applications have also been discussed. It can be concluded that latest progress in nanotechnology have enabled to design intricate systems with the ability to deliver biologically active agents, promoting tissue repair and regeneration; thus, nanomaterials studied herein have shown great potential to serve as immunomodulatory agents in the area of tissue engineering.

Green Synthesis of Metal and Metal Oxide Nanoparticles: A Review of the Principles and Biomedical Applications

In recent years, interest in nanotechnology has increased exponentially due to enhanced progress and technological innovation. In tissue engineering, the development of metallic nanoparticles has been amplified, especially due to their antibacterial properties. Another important characteristic of metal NPs is that they enable high control over the features of the developed scaffolds (optimizing their mechanical strength and offering the controlled release of bioactive agents). Currently, the main concern related to the method of synthesis of metal oxide NPs is the environmental impact. The physical and chemical synthesis uses toxic agents that could generate hazards or exert carcinogenicity/environmental toxicity. Therefore, a greener, cleaner, and more reliable approach is needed. Green synthetic has come as a solution to counter the aforementioned limitations. Nowadays, green synthesis is preferred because it leads to the prevention/minimization of waste, the reduction of derivatives/pollution, and the use of non-toxic (safer) solvents. This method not only uses biomass sources as reducing agents for metal salts. The biomolecules also cover the synthesized NPs or act as in situ capping and reducing agents. Further, their involvement in the formation process reduces toxicity, prevents nanoparticle agglomeration, and improves the antimicrobial activity of the nanomaterial, leading to a possible synergistic effect. This study aims to provide a comprehensive review of the green synthesis of metal and metal oxide nanoparticles, from the synthesis routes, selected solvents, and parameters to their latest application in the biomedical field.

Novel Electroactive Mineralized Polyacrylonitrile/PEDOT:PSS Electrospun Nanofibers for Bone Repair Applications

Bone defect repair remains a critical challenge in current orthopedic clinical practice, as the available therapeutic strategies only offer suboptimal outcomes. Therefore, bone tissue engineering (BTE) approaches, involving the development of biomimetic implantable scaffolds combined with osteoprogenitor cells and native-like physical stimuli, are gaining widespread interest. Electrical stimulation (ES)-based therapies have been found to actively promote bone growth and osteogenesis in both in vivo and in vitro settings. Thus, the combination of electroactive scaffolds comprising conductive biomaterials and ES holds significant promise in improving the effectiveness of BTE for clinical applications. The aim of this study was to develop electroconductive polyacrylonitrile/poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PAN/PEDOT:PSS) nanofibers via electrospinning, which are capable of emulating the native tissue's fibrous extracellular matrix (ECM) and providing a platform for the delivery of exogenous ES. The resulting nanofibers were successfully functionalized with apatite-like structures to mimic the inorganic phase of the bone ECM. The conductive electrospun scaffolds presented nanoscale fiber diameters akin to those of collagen fibrils and displayed bone-like conductivity. PEDOT:PSS incorporation was shown to significantly promote scaffold mineralization in vitro. The mineralized electroconductive nanofibers demonstrated improved biological performance as observed by the significantly enhanced proliferation of both human osteoblast-like MG-63 cells and human bone marrow-derived mesenchymal stem/stromal cells (hBM-MSCs). Moreover, mineralized PAN/PEDOT:PSS nanofibers up-regulated bone marker genes expression levels of hBM-MSCs undergoing osteogenic differentiation, highlighting their potential as electroactive biomimetic BTE scaffolds for innovative bone defect repair strategies.

Lanthanum Oxide Nanoparticles Reinforced Collagen ƙ-Carrageenan Hydroxyapatite Biocomposite as Angio-Osteogenic Biomaterial for In Vivo Osseointegration and Bone Repair

A composite biomatrix fabricated with collagen, ƙ-carrageenan, hydroxyapatite reinforced with lanthanum oxide nanoparticles is explored as proangiogenic and osteogenic bone tissue repair biomaterial. The biomatrix shows increased physical and biological stability as observed from proteolytic degradation and thermal stability studies. The addition of lanthanum oxide nanoparticles facilitates good osseointegration coupled with simultaneous activation of proangiogenic properties to act as a bone mimicking material. The minimal level of reactive oxygen species and superior cytocompatibility help the as-synthesized biomatrix in achieving capillary migration into the bone micro environment. The composite biomatrix upregulates the expression of VEGF, VEGF-R2 genes in endothelial cells and osteopontin, osteocalcin in osteoblasts cells, respectively. The in vivo hard tissue repair experiment conducted in a rat model shows complete healing of the bone defect by eight weeks with the application of collagen-ƙ-carrageenan-hydroxyapatite-lanthanum oxide nanoparticle biomaterial when compared to the biomaterial made out of individual constituents alone. The biomaterial matrix gets biointegrated into the bone tissue and exerts its therapeutic value in bringing a faster osseo repair process. The study shows the feasibility of using rare-earth metal nanoparticles in combination with protein-polysaccharide biopolymers for bone regeneration.

Bioactive Glass Modified with Zirconium Incorporation for Dental Implant Applications: Fabrication, Structural, Electrical, and Biological Analysis

Implantology is crucial for restoring aesthetics and masticatory function in oral rehabilitation. Despite its advantages, certain issues, such as bacterial infection, may still arise that hinder osseointegration and result in implant rejection. This work aims to address these challenges by developing a biomaterial for dental implant coating based on 45S5 Bioglass^® modified by zirconium insertion. The structural characterization of the glasses, by XRD, showed that the introduction of zirconium in the Bioglass network at a concentration higher than 2 mol% promotes phase separation, with crystal phase formation. Impedance spectroscopy was used, in the frequency range of 10²-10⁶ Hz and the temperature range of 200-400 K, to investigate the electrical properties of these Bioglasses, due to their ability to store electrical charges and therefore enhance the osseointegration capacity. The electrical study showed that the presence of crystal phases, in the glass ceramic with 8 mol% of zirconium, led to a significant increase in conductivity. In terms of biological properties, the Bioglasses exhibited an antibacterial effect against Gram-positive and Gram-negative bacteria and did not show cytotoxicity for the Saos-2 cell line at extract concentrations up to 25 mg/mL. Furthermore, the results of the bioactivity test revealed that within 24 h, a CaP-rich layer began to form on the surface of all the samples. According to our results, the incorporation of 2 mol% of ZrO₂ into the Bioglass significantly improves its potential as a coating material for dental implants, enhancing both its antibacterial and osteointegration properties.

Mechanical, biocompatibility and antibacterial studies of gelatin/polyvinyl alcohol/silkfibre polymeric scaffold for bone tissue engineering

The current study focuses on the incorporation of natural polymers (gelatin, silk fibre) and synthetic (polyvinyl alcohol) polymer towards the fabrication of a novel composite for bone tissue engineering. The Electrospinning method was used to fabricate the novel gelatin/polyvinyl alcohol/silk fibre scaffold. XRD, FTIR and SEM-EDAX analysis was performed to characterize the composite. The characterized composite was investigated for its physical properties (porosity and mechanical studies) and biological studies (antimicrobial activity, hemocompatibility, bioactivity). The fabricated composite showed high porosity and the highest tensile strength of 34 MPa, with elongation at a break of 35.82 for the composite. The antimicrobial activity of the composite was studied and the zone of inhibition was measured around 51 ± 0.54 for E. coli, 48 ± 0.48 for S. aureus and 50 ± 0.26 for C. albicans. The hemolytic % was noted around 1.36 for the composite and the bioactivity assay revealed the formation of apatite on composite surfaces.

Effect of copper oxide nanoparticles and light-emitting diode irradiation on the cell viability and osteogenic/odontogenic differentiation of human stem cells from the apical papilla

OBJECTIVES

This experimental study aimed to assess the effect of copper oxide nanoparticles (CuONPs) and light-emitting diode (LED) irradiation on the cell viability and osteogenic/odontogenic differentiation of human SCAPs.

METHODS

After the culture of SCAPs, the effects of different concentrations of CuONPs on cell viability were evaluated by the methyl thiazolyl tetrazolium (MTT) assay after 24 and 48 h, and the optimal concentration was determined (n = 12). SCAPs were then divided into four groups based on the type of treatment: (I) no-treatment control group, (II) exposure to CuONPs, (III) LED irradiation (635 nm, 200 mW/cm²) for 30 s, and (IV) exposure to CuONPs combined with LED irradiation. CuONPs were synthesized by a green technique, which was based on reduction and simultaneous stability of copper ions by using the pomegranate peel extract. After treatments, the expression of osteogenic/odontogenic markers including dentin sialophosphoprotein (DSPP), bone sialoprotein (BSP), alkaline phosphatase (ALP), and dentin matrix acidic phosphoprotein 1 (DMP1) was evaluated in all four groups using quantitative real-time polymerase chain reaction (PCR) (n = 16). Also, osteogenic differentiation of SCAPs was evaluated qualitatively by alizarin red staining (ARS) to assess the matrix mineralization (n = 4). SPSS version 18 was used for data evaluation. The Kruskal-Wallis and Mann-Whitney tests were used to compare the groups.

RESULTS

Exposure to 1 µg/mL CuONPs resulted in maximum viability of SCAPs. Concentrations of CuONPs over 10 µg/mL significantly decreased the viability of SCAPs. Real-time PCR showed that the expression of DMP1, BSP, ALP, and DSPP in CuONPs + LED and LED groups was significantly higher than that in CuONPs and control groups at both 24 and 48 h (P < 0.05). The density of ARS increased in all experimental groups after 24 h, and in CuONPs + LED and CuONPs groups after 48 h, compared to the control group.

CONCLUSION

Addition of CuONPs and LED irradiation of SCAPs in the culture medium significantly enhanced their osteogenic/odontogenic differentiation.

Scaffold Using Chitosan, Agarose, Cellulose, Dextran and Protein for Tissue Engineering-A Review

Biological macromolecules like polysaccharides/proteins/glycoproteins have been widely used in the field of tissue engineering due to their ability to mimic the extracellular matrix of tissue. In addition to this, these macromolecules are found to have higher biocompatibility and no/lesser toxicity when compared to synthetic polymers. In recent years, scaffolds made up of proteins, polysaccharides, or glycoproteins have been highly used due to their tensile strength, biodegradability, and flexibility. This review is about the fabrication methods and applications of scaffolds made using various biological macromolecules, including polysaccharides like chitosan, agarose, cellulose, and dextran and proteins like soy proteins, zein proteins, etc. Biopolymer-based nanocomposite production and its application and limitations are also discussed in this review. This review also emphasizes the importance of using natural polymers rather than synthetic ones for developing scaffolds, as natural polymers have unique properties, like high biocompatibility, biodegradability, accessibility, stability, absence of toxicity, and low cost.

3D-printed MgO nanoparticle loaded polycaprolactone β-tricalcium phosphate composite scaffold for bone tissue engineering applications: In-vitro and in-vivo evaluation

Magnesium (Mg) plays an important role in controlling bone apatite structure and density and is a potential bioactive material in repairing critical-sized bone defects. In this study, we aimed to evaluate the effect of adding NanoMgO to polycaprolactone/beta-tricalcium phosphate (PCL/β-TCP) scaffolds on bone regeneration. Novel 3D-printed porous PCL/β-TCP composite scaffolds containing 10% nanoMgO were fabricated by fused deposition modeling (FDM) and compared with PCL/β-TCP (1:1) scaffolds (control). The morphology and physicochemical properties of the scaffolds were characterized by ATR-FTIR, XRD, scanning electron microscope-energy dispersive X-ray analysis (SEM-EDX), transmission-electron-microscopy (TEM), water contact angle, and compressive strength tests and correlated to its cytocompatibility and osteogenic capacity in-vitro. To evaluate in-vivo osteogenic capacity, bone-marrow-derived stem cell (BMSC)-loaded scaffolds were implanted into 8 mm rat critical-sized calvarial defects for 12 weeks. The hydrophilic scaffolds showed 50% porosity (pore size = 504 μm). MgO nanoparticles (91.5 ± 27.6 nm) were homogenously dispersed and did not adversely affect BMSCs' viability and differentiation. Magnesium significantly increased elastic modulus, pH, and degradation. New bone formation (NBF) in Micro-CT was 30.16 ± 0.31% and 23.56 ± 1.76% in PCL/β-TCP/nanoMgO scaffolds with and without BMSCs respectively, and 19.38 ± 2.15% and 15.75 ± 2.24% in PCL/β-TCP scaffolds with and without BMSCs respectively. Angiogenesis was least remarkable in PCL/β-TCP compared with other groups (p < .05). Our results suggest that the PCL/β-TCP/nanoMgO scaffold is a more suitable bone substitute compared to PCL/β-TCP in critical-sized calvarial defects.

Recent advances in carbon dots: synthesis and applications in bone tissue engineering

Bone tissue engineering (BTE), based on the perfect combination of seed cells, scaffold materials and growth factors, has shown unparalleled potential in the treatment of bone defects and related diseases. As the site of cell attachment, proliferation and differentiation, scaffolds composed of biomaterials play a crucial role in BTE. Over the past years, carbon dots (CDs), a new type of carbon-based nanomaterial, have attracted extensive research attention due to their good biocompatibility, unique optical properties, and abundant functional groups. This paper reviews recent research progress in the use of CDs in the field of BTE. Firstly, different preparation methods of CDs are summarized. Then, the properties and categories of CDs applied in BTE are described in detail. Subsequently, the applications of CDs in BTE, including osteogenesis, fluorescence tracing, phototherapy and antibacterial activity, are presented. Finally, the challenges and future perspectives of CDs in BTE are briefly discussed to give a comprehensive picture of CDs. This review provides a theoretical basis and advanced design strategies for the application of CDs in BTE.

Optimization of a silver-nanoprism conjugated with 3,3',5,5'-tetramethylbenzidine towards easy-to-make colorimetric analysis of acetaldehyde: a new platform towards rapid analysis of carcinogenic agents and environmental technology

Acetaldehyde acts as an important mediator in the metabolism of plants and animals; however, its abnormal level can cause problems in biological processes. Although acetaldehyde is found naturally in many organisms, exposure to high concentrations can have effects on the eyes, respiratory system, etc. Due to the importance of detecting acetaldehyde in environmental samples and biofluids, determination of its concentration is highly demanded. There are some reports showing exposure to high concentrations of acetaldehyde for a long time can increase the risk of cancer by reacting with DNA. In this work, we presented a novel colorimetric method for rapid and sensitive detection of acetaldehyde with high reproducibility using different AgNPs with various morphologies. The redox reaction between AgNPs, 3,3',5,5'-tetramethylbenzidine (TMB) solution, and analytes endows a color change in 15 minutes that is detectable by the naked eye. UV spectrophotometry was further used for quantitative analysis. An iron mold with a hexagonal pattern and liquid paraffin were also used to prepare the paper-based microfluidic substrate, as a low cost, accessible, and rapid detection tool. Different types of AgNPs showed different lower limits of quantification (LLOQ). The AgNPs-Cit and AgNPrs could identify acetaldehyde with linear range of 10^-7 to 10 M and an LLOQ of 10^-7 M. The AgNWs showed the best color change activity with a linear range 10^-5 to 10 M and the lowest diagnostic limit is 10^-5 M. Finally, analysis of human biofluids as real samples were successfully performed using this system.

Osteoimmunomodulatory Nanoparticles for Bone Regeneration

Treatment of large bone fractures remains a challenge for orthopedists. Bone regeneration is a complex process that includes skeletal cells such as osteoblasts, osteoclasts, and immune cells to regulate bone formation and resorption. Osteoimmunology, studying this complicated process, has recently been used to develop biomaterials for advanced bone regeneration. Ideally, a biomaterial shall enable a timely switch from early stage inflammatory (to recruit osteogenic progenitor cells) to later-stage anti-inflammatory (to promote differentiation and terminal osteogenic mineralization and model the microstructure of bone tissue) in immune cells, especially the M1-to-M2 phenotype switch in macrophage populations, for bone regeneration. Nanoparticle (NP)-based advanced drug delivery systems can enable the controlled release of therapeutic reagents and the delivery of therapeutics into specific cell types, thereby benefiting bone regeneration through osteoimmunomodulation. In this review, we briefly describe the significance of osteoimmunology in bone regeneration, the advancement of NP-based approaches for bone regeneration, and the application of NPs in macrophage-targeting drug delivery for advanced osteoimmunomodulation.

Advanced bioactive nanomaterials for diagnosis and treatment of major chronic diseases

With the rapid innovation of nanoscience and technology, nanomaterials have also been deeply applied in the medical and health industry and become one of the innovative methods to treat many diseases. In recent years, bioactive nanomaterials have attracted extensive attention and have made some progress in the treatment of some major chronic diseases, such as nervous system diseases and various malignant tumors. Bioactive nanomaterials depend on their physical and chemical properties (crystal structure, surface charge, surface functional groups, morphology, and size, etc.) and direct produce biological activity and play to the role of the treatment of diseases, compared with the traditional nanometer pharmaceutical preparations, biological active nano materials don't exert effects through drug release, way more directly, also is expected to be more effective for the treatment of diseases. However, further studies are needed in the evaluation of biological effects, fate in vivo, structure-activity relationship and clinical transformation of bionanomaterials. Based on the latest research reports, this paper reviews the application of bioactive nanomaterials in the diagnosis and treatment of major chronic diseases and analyzes the technical challenges and key scientific issues faced by bioactive nanomaterials in the diagnosis and treatment of diseases, to provide suggestions for the future development of this field.

Antimicrobial and Pro-Osteogenic Coaxially Electrospun Magnesium Oxide Nanoparticles-Polycaprolactone /Parathyroid Hormone-Polycaprolactone Composite Barrier Membrane for Guided Bone Regeneration

Introduction

An antibacterial and pro-osteogenic coaxially electrospun nanofiber guided bone regeneration (GBR) membrane was fabricated to satisfy the complicated and phased requirements of GBR process.

Methods

In this study, we synthesize dual-functional coaxially electrospun nanofiber GBR membranes by encapsulating parathyroid hormone (PTH) in the core layer and magnesium oxide nanoparticles (MgONPs) in the shell layer (MgONPs-PCL/PTH-PCL). Herein, the physicochemical characterization of MgONPs-PCL/PTH-PCL, the release rates of MgONPs and PTH, and antibacterial efficiency of the new membrane were evaluated. Furthermore, the pro-osteogenicity of the membranes was assessed both in-vitro and in-vivo.

Results

We successfully fabricated a coaxially electrospun nanofiber MgONPs-PCL/PTH-PCL membrane with the majority of nanofibers (>65%) ranged from 0.40~0.60μm in diameter. MgONPs-PCL/PTH-PCL showed outstanding antibacterial potential against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) through the release of MgONPs. We also discovered that the incorporation of MgONPs significantly prolonged the release of PTH. Furthermore, both the in-vivo and in-vitro studies demonstrated that high dosage of PTH promoted pro-osteogenicity of the membrane to improve bone regeneration efficacy with the presence of MgONPs.

Conclusion

The new composite membrane is a promising approach to enhance bone regeneration in periodontitis or peri-implantitis patients with large-volume bone defects.

Electrospinning Inorganic Nanomaterials to Fabricate Bionanocomposites for Soft and Hard Tissue Repair

Tissue engineering (TE) has attracted the widespread attention of the research community as a method of producing patient-specific tissue constructs for the repair and replacement of injured tissues. To date, different types of scaffold materials have been developed for various tissues and organs. The choice of scaffold material should take into consideration whether the mechanical properties, biodegradability, biocompatibility, and bioresorbability meet the physiological properties of the tissues. Owing to their broad range of physico-chemical properties, inorganic materials can induce a series of biological responses as scaffold fillers, which render them a good alternative to scaffold materials for tissue engineering (TE). While it is of worth to further explore mechanistic insight into the use of inorganic nanomaterials for tissue repair, in this review, we mainly focused on the utilization forms and strategies for fabricating electrospun membranes containing inorganic components based on electrospinning technology. A particular emphasis has been placed on the biological advantages of incorporating inorganic materials along with organic materials as scaffold constituents for tissue repair. As well as widely exploited natural and synthetic polymers, inorganic nanomaterials offer an enticing platform to further modulate the properties of composite scaffolds, which may help further broaden the application prospect of scaffolds for TE.

Bench-to-bedside: Feasibility of nano-engineered and drug-delivery biomaterials for bone-anchored implants and periodontal applications

Nanotechnology and drug-release biomaterials have been thoroughly explored in the last few years aiming to develop specialized clinical treatments. However, it is rare to find biomaterials associated with drug delivery properties in the current dental market for application in oral bone- and periodontal-related procedures. The gap between basic scientific evidence and translation to a commercial product remains wide. Several challenges have been reported regarding the clinical translation of biomaterials with drug-delivery systems (BDDS) and nanofeatures. Therefore, processes for BDDS development, application in preclinical models, drug delivery doses, sterilization processes, storage protocols and approval requirements were explored in this review, associated with tentative solutions for these issues. The diversity of techniques and compounds/molecules applied to develop BDDS demands a case-by-case approach to manufacturing and validating a commercial biomaterial. Promising outcomes such as accelerated tissue healing and higher antibacterial response have been shown through basic and preclinical studies using BDDS and nano-engineered biomaterials; however, the adequate process for sterilization, storage, cost-effectiveness and possible cytotoxic effects remains unclear for multifunctional biomaterials incorporated with different chemical compounds; then BDDSs are rarely translated into products. The future benefits of BDDS and nano-engineered biomaterials have been reported suggesting personalized clinical treatment and a promising reduction in the use of systemic antibiotics. Finally, the launch of these specialized biomaterials with solid data and controlled traceability onto the market will generate strong specificity for healthcare treatments.

Pectin Based Hydrogels for Drug Delivery Applications: A Mini Review

Over the past few decades, hydrogel systems using natural polymers have been expansively employed in drug delivery applications. Among the various reported biopolymer-based hydrogel drug delivery systems, pectin (Pec) is an exceptional natural polymer due to its unique functionalities and excellent properties such as biocompatibility, biodegradability, low-cost, and simple gelling capability, which has received considerable interest in the drug delivery fields. Since there is an increasing need for biomaterials with unique properties for drug delivery applications, in this review, hydrogels fabricated from natural pectin polymers were thoroughly investigated. Additionally, the present mini review aims to bring collectively more concise ways such as sources, extraction, properties, and various forms of Pec based hydrogel drug delivery systems and their toxicity concerns are summarized. Finally, the potential objectives and challenges based on pectin-based hydrogel drug delivery systems are also discussed.

Nanomaterials supported by polymers for tissue engineering applications: A review

In the biomedical sciences, particularly in wound healing, tissue engineering, and regenerative medicine, the development of natural-based biomaterials as a carrier has revealed a wide range of advantages. Tissue engineering is one of the therapeutic approaches used to replace damaged tissue. Polymers have received a lot of attention for their beneficial interactions with cells, but they have some drawbacks, such as poor mechanical properties. Due to their relatively large surface area, nanoparticles can cause significant changes in polymers and improve their mechanical properties. The nanoparticles incorporated into biomaterial scaffolds have been associated with positive effects on cell adhesion, viability, proliferation, and migration in the majority of studies. This review paper discusses recent applications of polymer-nanoparticle composites in the development of tissue engineering scaffolds, as well as the effects of these nanomaterials in the fields of cardiovascular, neural, bone, and skin tissue engineering.

Bone Tissue Engineering Scaffolds: Function of Multi-Material Hierarchically Structured Scaffolds

Bone tissue engineering (BTE) is a topic of interest for the last decade, and advances in materials, processing techniques, and the understanding of bone healing pathways have opened new avenues of research. The dual responsibility of BTE scaffolds in providing load-bearing capability and interaction with the local extracellular matrix to promote bone healing is a challenge in synthetic scaffolds. This article describes the usage and processing of multi-materials and hierarchical structures to mimic the structure of natural bone tissues to function as bioactive and load-bearing synthetic scaffolds. The first part of this literature review describes the physiology of bone healing responses and the interactions at different stages of bone repair. The following section reviews the available literature on biomaterials used for BTE scaffolds followed by some multi-material approaches. The next section discusses the impact of the scaffold's structural features on bone healing and the necessity of a hierarchical distribution in the scaffold structure. Finally, the last section of this review highlights the emerging trends in BTE scaffold developments that can inspire new tissue engineering strategies and truly develop the next generation of synthetic scaffolds.

Design, Fabrication, and Application of Mini-Scaffolds for Cell Components in Tissue Engineering

The concept of "lockyballs" or interlockable mini-scaffolds fabricated by two-photon polymerization from biodegradable polymers for the encagement of tissue spheroids and their delivery into the desired location in the human body has been recently introduced. In order to improve control of delivery, positioning, and assembly of mini-scaffolds with tissue spheroids inside, they must be functionalized. This review describes the design, fabrication, and functionalization of mini-scaffolds as well as perspectives on their application in tissue engineering for precisely controlled cell and mini-tissue delivery and patterning. The development of functionalized mini-scaffolds advances the original concept of "lockyballs" and opens exciting new prospectives for mini-scaffolds' applications in tissue engineering and regenerative medicine and their eventual clinical translation.

Role of Iron Oxide (Fe2O3) Nanocomposites in Advanced Biomedical Applications: A State-of-the-Art Review

Nanomaterials have demonstrated a wide range of applications and recently, novel biomedical studies are devoted to improving the functionality and effectivity of traditional and unmodified systems, either drug carriers and common scaffolds for tissue engineering or advanced hydrogels for wound healing purposes. In this regard, metal oxide nanoparticles show great potential as versatile tools in biomedical science. In particular, iron oxide nanoparticles with different shape and sizes hold outstanding physiochemical characteristics, such as high specific area and porous structure that make them idoneous nanomaterials to be used in diverse aspects of medicine and biological systems. Moreover, due to the high thermal stability and mechanical strength of Fe₂O₃, they have been combined with several polymers and employed for various nano-treatments for specific human diseases. This review is focused on summarizing the applications of Fe₂O₃-based nanocomposites in the biomedical field, including nanocarriers for drug delivery, tissue engineering, and wound healing. Additionally, their structure, magnetic properties, biocompatibility, and toxicity will be discussed.

A concise review on implications of silver nanoparticles in bone tissue engineering

Skeletal disorders represent a variety of degenerative diseases that affect bone and cartilage homeostasis. The regenerative capacity of bone is affected in osteoporosis, osteoarthritis, rheumatoid arthritis, bone fractures, congenital defects, and bone cancers. There is no viable, non-invasive treatment option and bone regeneration requires surgical intervention with the implantation of bone grafts. Incorporating nanoparticles in bone grafts have improved fracture healing by providing fine structures for bone tissue engineering. It is currently a revolutionary finding in the field of regenerative medicine. Silver nanoparticles (AgNPs) have garnered particular attention due to their well-known anti-microbial and potential osteoinductive properties. In addition, AgNPs have been demonstrated to regulate the proliferation and differentiation of mesenchymal stem cells (MSCs) involved in bone regeneration. Furthermore, AgNPs have shown toxicity towards cancer cells derived from bone. In the last decade, there have been multiple studies focusing on the effect of nanoparticles on the proliferation and/or differentiation of MSCs and bone cancer cells; however, the specific studies with AgNPs are limited. Although the reported investigations show promising in vitro and in vivo potential of AgNPs for application in bone regeneration, more studies are required to ensure their implications in bone tissue engineering. This review aims to highlight the current advances related to the production of AgNPs and their effect on MSCs and bone cancer cells, which will potentiate their possible implications in orthopedics. Moreover, this review article evaluates the future of AgNPs in bone tissue engineering.

Conductive and Semiconductive Nanocomposite-Based Hydrogels for Cardiac Tissue Engineering

Cardiovascular disease is the leading cause of death worldwide and the most common cause is myocardial infarction. Therefore, appropriate approaches should be used to repair damaged heart tissue. Recently, cardiac tissue engineering approaches have been extensively studied. Since the creation of the nature of cardiovascular tissue engineering, many advances have been made in cellular and scaffolding technologies. Due to the hydrated and porous structures of the hydrogel, they are used as a support matrix to deliver cells to the infarct tissue. In heart tissue regeneration, bioactive and biodegradable hydrogels are required by simulating native tissue microenvironments to support myocardial wall stress in addition to preserving cells. Recently, the use of nanostructured hydrogels has increased the use of nanocomposite hydrogels and has revolutionized the field of cardiac tissue engineering. Therefore, to overcome the limitation of the use of hydrogels due to their mechanical fragility, various nanoparticles of polymers, metal, and carbon are used in tissue engineering and create a new opportunity to provide hydrogels with excellent properties. Here, the types of synthetic and natural polymer hydrogels, nanocarbon-based hydrogels, and other nanoparticle-based materials used for cardiac tissue engineering with emphasis on conductive nanostructured hydrogels are briefly introduced.

Medical high-entropy alloy: Outstanding mechanical properties and superb biological compatibility

Medical metal implants are required to have excellent mechanical properties and high biocompatibility to handle the complex human environment, which is a challenge that has always existed for traditional medical metal materials. Compared to traditional medical alloys, high entropy alloys (HEAs) have a higher design freedom to allow them to carry more medical abilities to suit the human service environment, such as low elastic modulus, high biocompatible elements, potential shape memory capability. In recent years, many studies have pointed out that bio-HEAs, as an emerging medical alloy, has reached or even surpassed traditional medical alloys in various medical properties. In this review, we summarized the recent reports on novel bio-HEAs for medical implants and divide them into two groups according the properties, namely mechanical properties and biocompatibility. These new bio-HEAs are considered hallmarks of a historic shift representative of a new medical revolution.