Additive Manufacturing of Biomaterials, Tissues, and Organs

Influence of the Cortical Layer Thickness and Trabecular Layer Pattern Density on 3D-Printed Femur Strength

This paper presents the process of preparing and conducting a uniaxial compression test, developing the results, and determining the compressive strength of a femur made using 3D printing technology. The study considers the variable thickness of the outer layer-imitating cortical bone tissue-and the varying density of the inner layer-imitating trabecular bone tissue-which, with further analysis, may aim to replicate different states of osteoporosis. The compressive strength of the bones varied depending on the thickness of the outer layer and the filling degree. Failure patterns were observed, corresponding to different variants of the produced bones. The predominant failure pattern was the fracture of the femoral head or neck at the proximal end of the femur. The results were compared with previous studies on commercial femur bones, as well as those created using 3D printing technology by other authors. The highest compressive strength was found in the bone with an outer layer thickness of 3.0 mm and 30% infill, with a value of 4778 N. A very similar compressive strength was recorded for the bone with an outer thickness of 2.1 mm and 30% infill, reaching 4519 N. The lowest compressive strength, 2116 N, was observed in the bone with an outer thickness of 1.2 mm and 20% infill.

Advanced collagen-based scaffolds for cartilage and osteochondral regeneration: A review

Osteoarthritis (OA), a prevalent degenerative joint disease, presents a formidable challenge to human health due to its complex pathophysiology. Despite various clinical treatments, a definitive cure for OA remains elusive, leaving patients with only symptomatic relief. Tissue engineering has emerged as a promising approach for OA treatment, offering the potential to restore damaged cartilage and osteochondral tissues. Collagen-based scaffolds, renowned for their superior biocompatibility and bioactivity, hold significant potential in promoting effective cartilage and osteochondral regeneration. Over the past decades, substantial progress has been made in the design and clinical translation of collagen-based scaffolds for cartilage and osteochondral tissue engineering. However, no comprehensive review has yet addressed the application of collagen scaffold materials for OA treatment. This review highlights the advanced fabrication of collagen-based scaffolds, including porous matrices, hydrogels, and microspheres, and their integration with cells, growth factors, and pharmaceuticals for OA therapy. Additionally, it examines the clinical translation of collagen-integrated constructs for managing OA. With continued innovation, collagen-enriched scaffolds are expected to play a pivotal role in improving outcomes for OA patients.

Redefining Medical Applications with Safe and Sustainable 3D Printing

Additive manufacturing (AM) has revolutionized biomedical applications by enabling personalized designs, intricate geometries, and cost-effective solutions. This progress stems from interdisciplinary collaborations across medicine, biomaterials, engineering, artificial intelligence, and microelectronics. A pivotal aspect of AM is the development of materials that respond to stimuli such as heat, light, moisture, and chemical changes, paving the way for intelligent systems tailored to specific needs. Among the materials employed in AM, polymers have gained prominence due to their flexibility, synthetic versatility, and broad property spectrum. Their adaptability has made them the most widely used material class in AM processes, offering the potential for diverse applications, including surgical tools, structural composites, photovoltaic devices, and filtration systems. Despite this, integrating multiple polymer systems to achieve multifunctional and dynamic performance remains a significant challenge, highlighting the need for further research. This review explores the foundational principles of AM, emphasizing its application in tissue engineering and medical technologies. It provides an in-depth analysis of polymer systems, besides inorganic oxides and bioinks, and examines their unique properties, advantages, and limitations within the context of AM. Additionally, the review highlights emerging techniques like rapid prototyping and 3D printing, which hold promise for advancing biomedical applications. By addressing the critical factors influencing AM processes and proposing innovative approaches to polymer integration, this review aims to guide future research and development in the field. The insights presented here underscore the transformative potential of AM in creating dynamic, multifunctional systems to meet evolving biomedical and healthcare demands.

Application of 3D printing in veterinarian science

This article explores the transformative impact of 3D printing technology in veterinary medicine. It focuses on applications in various areas such as prosthetics and surgical planning. 3D printing allows for the creation of customized solutions for each animal, thus improving treatment outcomes and reducing surgical risks. Case studies demonstrate the successful adoption of this technology. It highlights innovations that improve patient care and improve veterinary practice. The discussion highlights the future potential of 3D printing in the advancement of veterinary medicine. It also considers ethical and practical challenges.

Evolution of temporomandibular joint reconstruction: from autologous tissue transplantation to alloplastic joint replacement

The reconstruction of the temporomandibular joint presents a multifaceted clinical challenge in the realm of head and neck surgery, underscored by its relatively infrequent occurrence and the lack of comprehensive clinical guidelines. This review aims to elucidate the available approaches for TMJ reconstruction, with a particular emphasis on recent groundbreaking advancements. The current spectrum of TMJ reconstruction integrates diverse surgical techniques, such as costochondral grafting, coronoid process grafting, revascularized fibula transfer, transport distraction osteogenesis, and alloplastic TMJ replacement. Despite the available options, a singular, universally accepted 'gold standard' for reconstructive techniques or materials remains elusive in this field. Our review comprehensively summarizes the current available methods of TMJ reconstruction, focusing on both autologous and alloplastic prostheses. It delves into the differences of each surgical technique and outlines the implications of recent technological advances, such as 3D printing, which hold the promise of enhancing surgical precision and patient outcomes. This evolutionary progress aims not only to improve the immediate results of reconstruction but also to ensure the long-term health and functionality of the TMJ, thereby improving the quality of life for patients with end-stage TMJ disorders.

Influence of Processing Parameters on Additively Manufactured Architected Cellular Metals: Emphasis on Biomedical Applications

Laser powder bed fusion (LPBF) has emerged as a transformative additive manufacturing technique for fabricating architected cellular metallic structures, offering tailored properties for diverse biomedical applications. These structures are particularly well-suited for bone implants, scaffolds, and other load-bearing medical devices due to their ability to achieve lightweight designs, enhanced mechanical properties, and customized geometries. However, the complex interactions between LPBF process parameters and the resulting structural and mechanical properties pose significant challenges in achieving the precision and reliability required for clinical applications. This review provides a comprehensive analysis of the effects of LPBF process parameters, including laser power, scanning speed, and layer thickness, on key attributes such as dimensional accuracy, density, surface roughness, and microstructure. Their influence on the mechanical performance, including strength, fatigue resistance, and functional properties, is critically examined, with specific attention to biomedical relevance. The impact of lattice design factors, such as topology, unit cell size, and orientation, is also discussed, underscoring their role in optimizing biocompatibility and structural integrity for medical applications. Challenges such as surface defects, geometric inaccuracies, and microstructural inconsistencies are highlighted as key barriers to the broader adoption of LPBF in biomedical fields. Future perspectives focus on advancing LPBF technologies through process optimization and integration with advanced computational tools, such as machine learning, to enable efficient manufacturing of complex, patient-specific architectures. By addressing these challenges, LPBF has the potential to revolutionize the development of next-generation biomaterials, tailored to meet evolving clinical needs and improve patient outcomes.

Controlling Mechanical Properties of Medical-Grade Scaffolds through Electrospinning Parameter Selection

Electrospinning (ES) is a versatile process mode for creating fibrous materials with various structures that have broad applications ranging from regenerative medicine to tissue engineering and surgical mesh implants. The recent commercialization of this technology for implant use has driven the use of resorbable electrospun products. Resorbable electrospun meshes offer great promise as temporary implants that can utilize the layer upon layer method of additive manufacturing to incorporate porosity as a function of process parameters into a scaffold structure. The interconnected porosity and feature size known to ES have previously been observed to hold great potential for simulating the natural cellular environment of soft tissue. This microstructure, proper degradation kinetics, and mechanical properties combine to provide the design basis for artificial tissue structures that could aid in not only wound healing but also true tissue engineering and regenerative medicine. While current advancement in the field is understood to be limited by material properties, the importance of optimizing mechanical properties with currently available materials should not be overlooked. This work investigated the process parameter effects and interactions that control the structure-property relationship for a range of medical-grade aliphatic polyester materials with a range of intrinsic properties. An ε-caprolactone homopolymer (PCL), l-lactide homopolymer (PLLA), and Lactoflex, a copolymer with intermediate properties relative to the homopolymers, were characterized before, during, and after the additive manufacturing process. The interacting effects of process parameters, distance to collector, and dispensing rate were shown to produce variable-density, nonwoven scaffold structures. The resorbable mesh scaffolds of PLLA, PCL, and Lactoflex demonstrated a broad range of mechanical properties (approximately 1-10 MPa ultimate tensile strength and 5-390 MPa tensile modulus). Postprocessing of scaffolds demonstrated removal of solvents and preservation of micrometer-sized features. Resorbable polymers and electrospinning can produce scaffold materials with excellent features and offer tremendous potential in the field of implantable resorbable devices.

The influence of viscosity of hydrogels on the spreading and migration of cells in 3D bioprinted skin cancer models

Various in vitro three-dimensional (3D) tissue culture models of human and diseased skin exist. Nevertheless, there is still room for the development and improvement of 3D bioprinted skin cancer models. The need for reproducible bioprinting methods, cell samples, biomaterial inks, and bioinks is becoming increasingly important. The influence of the viscosity of hydrogels on the spreading and migration of most types of cancer cells is well studied. There are however limited studies on the influence of viscosity on the spreading and migration of cells in 3D bioprinted skin cancer models. In this review, we will outline the importance of studying the various types of skin cancers by using 3D cell culture models. We will provide an overview of the advantages and disadvantages of the various 3D bioprinting technologies. We will emphasize how the viscosity of hydrogels relates to the spreading and migration of cancer cells. Lastly, we will give an overview of the specific studies on cell migration and spreading in 3D bioprinted skin cancer models.

Revolutionizing bone tumor management: cutting-edge breakthroughs in limb-saving treatments

Limb salvage surgery has revolutionized the approach to bone tumors in orthopedic oncology, steering away from historical amputations toward preserving limb function and enhancing patient quality of life. This transformative shift underscores the delicate balance between tumor eradication and optimal postoperative function. Primary and metastatic bone tumors present challenges in early detection, differentiation between benign and malignant tumors, preservation of function, and the risk of local recurrence. Conventional methods, including surgery, radiation therapy, chemotherapy, and targeted therapies, have evolved with a heightened focus on personalized medicine. A groundbreaking development in limb salvage surgery is the advent of 3D-printed patient-specific implants, which significantly enhance anatomical precision, stability, and fixation. These implants reduce soft tissue disruption and the associated risks, fostering improved osseointegration and correction of deformities for a more natural and functional postoperative outcome. Biological and molecular research has reshaped the understanding of bone tumors, guiding surgical interventions with advancements such as genomic profiling, targeted intraoperative imaging, precision targeting of molecular pathways, and immunotherapy tailored to individual tumor characteristics. In the realm of imaging technologies, MRI, CT scans, and intraoperative navigation systems have redefined preoperative planning, minimizing collateral damage and optimizing outcomes through accurate resections. Postoperative rehabilitation plays a crucial role in restoring function and improving the quality of life. Emphasizing early mobilization, effective pain management, and a multidisciplinary approach, rehabilitation addresses the physical, psychological, and social aspects of recovery. Looking ahead, future developments may encompass advanced biomaterials, smart implants, AI algorithms, robotics, and regenerative medicine. Challenges lie in standardization, cost-effectiveness, accessibility, long-term outcome assessment, mental health support, and fostering global collaboration. As research progresses, limb salvage surgery emerges not just as a preservation tool but as a transformative approach, restoring functionality, resilience, and hope in the recovery journey. This review summarizes the recent advances in limb salvage therapy for bone tumors over the past decade.

Experimental Evaluation of the Effects of Discrete-Grading-Induced Discontinuities on the Material Properties of Functionally Graded Ti-6Al-4V Lattices

In this study, we compared the material properties of linearly and sharply graded Ti6Al4V additively manufactured samples to investigate whether the more severe discontinuities caused by sharp grading can reduce performance. We performed compression testing with digital image correlation (DIC) in two loading directions for each grading design to simulate iso-stress and iso-strain conditions. We extracted the elastic stiffness, yield strength, yield strain, and energy absorption capacity of each sample. In addition, we used micro-computed tomography (micro-CT) imaging to examine the printing quality and dimensional accuracy. We found that sharply graded struts have a 12.95% increase in strut cross-sectional areas, whereas linearly graded struts produced an average of 49.24% increase compared to design. However, sharply graded and linearly graded FGL samples do not have statistically significant differences in elastic stiffness and yield strength. For the iso-strain condition, the average DIC-corrected stiffnesses for linearly and sharply graded samples were 6.15 GPa and 5.43 GPa, respectively (p = 0.4466), and the yield stresses were 290.4 MPa and 291.2 MPa, respectively (p = 0.5734). Furthermore, we confirmed different types of printing defects using micro-CT, including defective pores and disconnected struts. These results suggest that the loss of material properties caused by manufacturing defects outweighs the adverse effects of discrete-grading-induced discontinuities.

First experiences of a hospital-based 3D printing facility - an analytical observational study

PURPOSE

To identify the clinical impact and potential benefits of in-house 3D-printed objects through a questionnaire, focusing on three principal areas: patient education; interdisciplinary cooperation; preoperative planning and perioperative execution.

MATERIALS AND METHODS

Questionnaires were sent from January 2021 to August 2022. Participants were directed to rate on a scale from 1 to 10.

RESULTS

The response rate was 43%. The results of the rated questions are averages. 84% reported using 3D-printed objects in informing the patient about their condition/procedure. Clinician-reported improvement in patient understanding of their procedure/disease was 8.1. The importance of in-house placement was rated 9.2. 96% reported using the 3D model to confer with colleagues. Delay in treatment due to 3D printing lead-time was 1.8. The degree with which preoperative planning was altered was 6.9. The improvement in clinician perceived preoperative confidence was 8.3. The degree with which the scope of the procedure was affected, in regard to invasiveness, was 5.6, wherein a score of 5 is taken to mean unchanged. Reduction in surgical duration was rated 5.7.

CONCLUSION

Clinicians report the utilization of 3D printing in surgical specialties improves procedures pre- and intraoperatively, has a potential for increasing patient engagement and insight, and in-house location of a 3D printing center results in improved interdisciplinary cooperation and allows broader access with only minimal delay in treatment due to lead-time.

Incorporation of Controlled Release Systems Improves the Functionality of Biodegradable 3D Printed Cardiovascular Implants

New horizons in cardiovascular research are opened by using 3D printing for biodegradable implants. This additive manufacturing approach allows the design and fabrication of complex structures according to the patient's imaging data in an accurate, reproducible, cost-effective, and quick manner. Acellular cardiovascular implants produced from biodegradable materials have the potential to provide enough support for in situ tissue regeneration while gradually being replaced by neo-autologous tissue. Subsequently, they have the potential to prevent long-term complications. In this Review, we discuss the current status of 3D printing applications in the development of biodegradable cardiovascular implants with a focus on design, biomaterial selection, fabrication methods, and advantages of implantable controlled release systems. Moreover, we delve into the intricate challenges that accompany the clinical translation of these groundbreaking innovations, presenting a glimpse of potential solutions poised to enable the realization of these technologies in the realm of cardiovascular medicine.

Three-Dimensional Printing and Bioprinting in Renal Transplantation and Regenerative Medicine: Current Perspectives

For patients with end-stage kidney disease (ESKD), renal transplantation is the treatment of choice, constituting the most common solid organ transplantation. This study aims to provide a comprehensive review regarding the application of three-dimensional (3D) printing and bioprinting in renal transplantation and regenerative medicine. Specifically, we present studies where 3D-printed models were used in the training of surgeons through renal transplantation simulations, in patient education where patients acquire a higher understanding of their disease and the proposed operation, in the preoperative planning to facilitate decision-making, and in fabricating customized, tools and devices. Three-dimensional-printed models could transform how surgeons train by providing surgical rehearsal platforms across all surgical specialties, enabling training with tissue realism and anatomic precision. The use of 3D-printed models in renal transplantations has shown a positive impact on surgical outcomes, including the duration of the operation and the intraoperative blood loss. Regarding 3D bioprinting, the technique has shown promising results, especially in the field of microfluidic devices, with the development of tissue demonstrating proximal tubules, glomerulus, and tubuloinerstitium function, and in renal organoid development. Such models can be applied for renal disease modeling, drug development, and renal regenerative medicine.

Microstructure and Biomechanical Properties in Selective Laser Melting of Porous Metal Implants

Two kinds of porous structure design strategies, ring-support (RS) and column-support (CS), are proposed for human implants. The accurate design of porosity is realized by adjusting the pore characteristics, such as strut diameter, pore diameter, and unit size. Porous specimens with porosity of 50%, 60%, 70%, and 80% were prepared by selective laser melting. The three-dimensional pore structure is basically consistent with the design characteristics, and the measured porosity is slightly lower than design value. The microstructure, microhardness, and friction and wear properties of the samples were studied. The results show that the performance along the scanning orientation is slightly better than that along the forming orientation. The compression and dynamic elastic modulus of porous specimens with different structures and porosities were analyzed. The CS porous with 60-80% porosity has suitable compressive strength and elastic modulus, which is close to that of human tissue, and effectively avoids the stress shielding phenomenon.

Emerging Strategies for the Biofabrication of Multilayer Composite Amniotic Membranes for Biomedical Applications

The amniotic membrane (AM) is the innermost part of the fetal placenta, which surrounds and protects the fetus. Due to its structural components (stem cells, growth factors, and proteins), AMs display unique biological properties and are a widely available and cost-effective tissue. As a result, AMs have been used for a century as a natural biocompatible dressing for healing corneal and skin wounds. To further increase its properties and expand its applications, advanced hybrid materials based on AMs have recently been developed. One existing approach is to combine the AM with a secondary material to create composite membranes. This review highlights the increasing development of new multilayer composite-based AMs in recent years and focuses on the benefits of additive manufacturing technologies and electrospinning, the most commonly used strategy, in expanding their use for tissue engineering and clinical applications. The use of AMs and multilayer composite-based AMs in the context of nerve regeneration is particularly emphasized and other tissue engineering applications are also discussed. This review highlights that these electrospun multilayered composite membranes were mainly created using decellularized or de-epithelialized AMs, with both synthetic and natural polymers used as secondary materials. Finally, some suggestions are provided to further enhance the biological and mechanical properties of these composite membranes.

Trends in Photopolymerizable Bioinks for 3D Bioprinting of Tumor Models

Three-dimensional (3D) bioprinting technologies involving photopolymerizable bioinks (PBs) have attracted enormous attention in recent times owing to their ability to recreate complex structures with high resolution, mechanical stability, and favorable printing conditions that are suited for encapsulating cells. 3D bioprinted tissue constructs involving PBs can offer better insights into the tumor microenvironment and offer platforms for drug screening to advance cancer research. These bioinks enable the incorporation of physiologically relevant cell densities, tissue-mimetic stiffness, and vascularized channels and biochemical gradients in the 3D tumor models, unlike conventional two-dimensional (2D) cultures or other 3D scaffold fabrication technologies. In this perspective, we present the emerging techniques of 3D bioprinting using PBs in the context of cancer research, with a specific focus on the efforts to recapitulate the complexity of the tumor microenvironment. We describe printing approaches and various PB formulations compatible with these techniques along with recent attempts to bioprint 3D tumor models for studying migration and metastasis, cell-cell interactions, cell-extracellular matrix interactions, and drug screening relevant to cancer. We discuss the limitations and identify unexplored opportunities in this field for clinical and commercial translation of these emerging technologies.

A Review on Multiplicity in Multi-Material Additive Manufacturing: Process, Capability, Scale, and Structure

Additive manufacturing (AM) has experienced exponential growth over the past two decades and now stands on the cusp of a transformative paradigm shift into the realm of multi-functional component manufacturing, known as multi-material AM (MMAM). While progress in MMAM has been more gradual compared to single-material AM, significant strides have been made in exploring the scientific and technological possibilities of this emerging field. Researchers have conducted feasibility studies and investigated various processes for multi-material deposition, encompassing polymeric, metallic, and bio-materials. To facilitate further advancements, this review paper addresses the pressing need for a consolidated document on MMAM that can serve as a comprehensive guide to the state of the art. Previous reviews have tended to focus on specific processes or materials, overlooking the overall picture of MMAM. Thus, this pioneering review endeavors to synthesize the collective knowledge and provide a holistic understanding of the multiplicity of materials and multiscale processes employed in MMAM. The review commences with an analysis of the implications of multiplicity, delving into its advantages, applications, challenges, and issues. Subsequently, it offers a detailed examination of MMAM with respect to processes, materials, capabilities, scales, and structural aspects. Seven standard AM processes and hybrid AM processes are thoroughly scrutinized in the context of their adaptation for MMAM, accompanied by specific examples, merits, and demerits. The scope of the review encompasses material combinations in polymers, composites, metals-ceramics, metal alloys, and biomaterials. Furthermore, it explores MMAM's capabilities in fabricating bi-metallic structures and functionally/compositionally graded materials, providing insights into various scale and structural aspects. The review culminates by outlining future research directions in MMAM and offering an overall outlook on the vast potential of multiplicity in this field. By presenting a comprehensive and integrated perspective, this paper aims to catalyze further breakthroughs in MMAM, thus propelling the next generation of multi-functional component manufacturing to new heights by capitalizing on the unprecedented possibilities of MMAM.

An overview of 3D printed metal implants in orthopedic applications: Present and future perspectives

With the ability to produce components with complex and precise structures, additive manufacturing or 3D printing techniques are now widely applied in both industry and consumer markets. The emergence of tissue engineering has facilitated the application of 3D printing in the field of biomedical implants. 3D printed implants with proper structural design can not only eliminate the stress shielding effect but also improve in vivo biocompatibility and functionality. By combining medical images derived from technologies such as X-ray scanning, CT, MRI, or ultrasonic scanning, 3D printing can be used to create patient-specific implants with almost the same anatomical structures as the injured tissues. Numerous clinical trials have already been conducted with customized implants. However, the limited availability of raw materials for printing and a lack of guidance from related regulations or laws may impede the development of 3D printing in medical implants. This review provides information on the current state of 3D printing techniques in orthopedic implant applications. The current challenges and future perspectives are also included.

Research on Properties of Silicone-Modified Epoxy Resin and 3D Printing Materials

A kind of organosilicon intermediate was prepared using isophorone diisocyanate (IPDI), hydroxyl silicone oil (HSO), and hydroxyethyl acrylate (HEA). The organosilicon modification of epoxy resin was realized by introducing a -Si-O- group into the side chain of epoxy resin by chemical grafting. The effects of organosilicon modification of epoxy resin on the mechanical properties systematically discuss its heat resistance and micromorphology. The results indicate that the curing shrinkage of the resin was decreased and the printing accuracy was improved. At the same time, the mechanical properties of the material are enhanced; the IS and elongation at break (EAB) are enhanced by 32.8 and 8.65%, respectively. The brittle fracture is changed to a ductile fracture, and the tensile strength (TS) of the material is decreased. The glass transition temperature (GTT) of the modified epoxy resin increased by 8.46 °C, and T_50% and T_max increased by 1.9 and 6 °C, respectively, indicating that the heat resistance of the modified epoxy resin was improved.

Challenges and Future Perspectives for Additively Manufactured Polylactic Acid Using Fused Filament Fabrication in Dentistry

Additive manufacturing (AM), which is also called rapid prototyping/3D printing/layered manufacturing, can be considered as a rapid conversion between digital and physical models. One of the most used materials in AM is polylactic acid (PLA), which has advantageous material properties such as biocompatibility, biodegradability, and nontoxicity. For many medical applications, it is considered as a leading biomaterial. In dentistry, in addition to its uses in dental models (education, teaching, simulation needs), it can be used for therapeutic objectives and tissue engineering. The fused filament fabrication (FFF) technique, also called fused deposition modeling (FDM), is widely used as an AM technique to perform complex and functional geometries directly from CAD files. In this review, the objective was to present the different challenges and future perspectives of this additively manufactured material by using FFF in dentistry areas. Some suggestions for future directions to extend to more dental applications (support structures, lattice structures, etc.) and to consider more criteria (sustainability, uncertainty etc.) will be discussed. Advanced studies such as machine learning (ML) techniques will be suggested to reduce the failure cases when using the additively manufactured PLA by FFF in dentistry.

Deformable titanium for acetabular revision surgery: a proof of concept

Custom-made triflange acetabular implants are increasingly used in complex revision surgery where supporting bone stock is diminished. In most cases these triflange cups induce stress-shielding. A new concept for the triflange is introduced that uses deformable porous titanium to redirect forces from the acetabular rim to the bone stock behind the implant and thereby reduces further stress-shielding. This concept is tested for deformability and primary stability.Three different designs of highly porous titanium cylinders were tested under compression to determine their mechanical properties. The most promising design was used to design five acetabular implants either by incorporating a deformable layer at the back of the implant or by adding a separate generic deformable mesh behind the implant. All implants were inserted into sawbones with acetabular defects followed by a cyclic compression test of 1800N for 1000 cycles.The design with a cell size of 4 mm and 0.2 mm strut thickness performed the best and was applied for the design of the acetabular implants. An immediate primary fixation was realized in all three implants with an incorporated deformable layer. One of the two implants with a separate deformable mesh needed fixation with screws. Cyclic tests revealed an average additional implant subsidence of 0.25 mm that occurred in the first 1000 cycles with minimal further subsidence thereafter.It is possible to realize primary implant fixation and stability in simulated large acetabular revision surgery using a deformable titanium layer behind the cup. Additional research is needed for further implementation of such implants in the clinic.

Cells-in-Touch: 3D Printing in Reconstruction and Modelling of Microscopic Biological Geometries for Education and Future Research Applications

Additive manufacturing (3D printing) and computer-aided design (CAD) still have limited uptake in biomedical and bioengineering research and education, despite the significant potential of these technologies. The utility of organ-scale 3D-printed models of living structures is widely appreciated, while the workflows for microscopy data translation into tactile accessible replicas are not well developed yet. Here, we demonstrate an accessible and reproducible CAD-based methodology for generating 3D-printed scalable models of human cells cultured in vitro and imaged using conventional scanning confocal microscopy with fused deposition modeling (FDM) 3D printing. We termed this technology CiTo-3DP (Cells-in-Touch for 3D Printing). As a proof-of-concept, we created dismountable CiTo-3DP models of human epithelial, mesenchymal, and neural cells by using selectively stained nuclei and cytoskeletal components. We also provide educational and research context for the presented cellular models. In the future, the CiTo-3DP approach can be adapted to different imaging and 3D printing modalities and comprehensively present various cell types, subcellular structures, and extracellular matrices. The resulting CAD and 3D printed models could be used for a broad spectrum of education and research applications.

3D and 4D Bioprinting Technologies: A Game Changer for the Biomedical Sector?

Bioprinting is an innovative and emerging technology of additive manufacturing (AM) and has revolutionized the biomedical sector by printing three-dimensional (3D) cell-laden constructs in a precise and controlled manner for numerous clinical applications. This approach uses biomaterials and varying types of cells to print constructs for tissue regeneration, e.g., cardiac, bone, corneal, cartilage, neural, and skin. Furthermore, bioprinting technology helps to develop drug delivery and wound healing systems, bio-actuators, bio-robotics, and bio-sensors. More recently, the development of four-dimensional (4D) bioprinting technology and stimuli-responsive materials has transformed the biomedical sector with numerous innovations and revolutions. This issue also leads to the exponential growth of the bioprinting market, with a value over billions of dollars. The present study reviews the concepts and developments of 3D and 4D bioprinting technologies, surveys the applications of these technologies in the biomedical sector, and discusses their potential research topics for future works. It is also urged that collaborative and valiant efforts from clinicians, engineers, scientists, and regulatory bodies are needed for translating this technology into the biomedical, pharmaceutical, and healthcare systems.

Structural Mechanical Properties of 3D Printing Biomimetic Bone Replacement Materials

One of the primary challenges in developing bone substitutes is to create scaffolds with mechanical properties that closely mimic those of regenerated tissue. Scaffolds that mimic the structure of natural cancellous bone are believed to have better environmental adaptability. In this study, we used the porosity and thickness of pig cancellous bone as biomimetic design parameters, and porosity and structural shape as differential indicators, to design a biomimetic bone beam scaffold. The mechanical properties of the designed bone beam model were tested using the finite element method (FEM). PCL/β-TCP porous scaffolds were prepared using the FDM method, and their mechanical properties were tested. The FEM simulation results were compared and validated, and the effects of porosity and pore shape on the mechanical properties were analyzed. The results of this study indicate that the PCL/β-TCP scaffold, prepared using FDM 3D printing technology for cancellous bone tissue engineering, has excellent integrity and stability. Predicting the structural stability using FEM is effective. The triangle pore structure has the most stability in both simulations and tests, followed by the rectangle and honeycomb shapes, and the diamond structure has the worst stability. Therefore, adjusting the porosity and pore shape can change the mechanical properties of the composite scaffold to meet the mechanical requirements of customized tissue engineering.

Additive Manufacturing of Carbon Using Commodity Polypropylene

Carbon materials are essential to the development of modern society with indispensable use in various applications, such as energy storage and high-performance composites. Despite great progress, on-demand carbon manufacturing with control over 3D macroscopic configuration is still an intractable challenge, hindering their direct use in many areas requiring structured materials and products. This work introduces a simple and scalable method to generate complex, large-scale carbon structures using easily accessible materials and technologies. 3D-printed, commercial polypropylene (PP) parts can be thermally stabilized through cracking-facilitated diffusion and crosslinking. The newly elucidated mechanism from this work allows thick PP parts to yield carbonaceous products with complex structures through a subsequent pyrolysis step. The approach for enabling PP-to-carbon conversion has consistent product yield and controlled dimensional shrinkage. Under optimized processing conditions, these PP-derived carbons exhibit robust mechanical properties and excellent joule heating performance, demonstrated by their versatile use as heating elements. Furthermore, this process can be extended to recycled PP, enabling the conversion of waste plastic materials to value-added products. This work provides an innovative approach to create structured carbon materials with direct access to complex geometry, which can be transformative to, and broadly benefit, many important technological applications.

A Review of the Benefits 3D Printing Brings to Patients with Neurological Diseases

This interdisciplinary review focuses on how flexible three-dimensional printing (3DP) technology can aid patients with neurological diseases. It covers a wide variety of current and possible applications ranging from neurosurgery to customizable polypill along with a brief description of the various 3DP techniques. The article goes into detail about how 3DP technology can aid delicate neurosurgical planning and its consequent outcome for patients. It also covers areas such as how the 3DP model can be utilized in patient counseling along with designing specific implants involved in cranioplasty and customization of a specialized instrument such as 3DP optogenetic probes. Furthermore, the review includes how a 3DP nasal cast can contribute to the development of nose-to-brain drug delivery along with looking into how bioprinting could be used for regenerating nerves and how 3D-printed drugs could offer practical benefits to patients suffering from neurological diseases via polypill.

Fish scale containing alginate dialdehyde-gelatin bioink for bone tissue engineering

The development of biomaterial inks suitable for biofabrication and mimicking the physicochemical properties of the extracellular matrix is essential for the application of bioprinting technology in tissue engineering (TE). The use of animal-derived proteinous materials, such as jellyfish collagen, or fish scale (FS) gelatin (GEL), has become an important pillar in biomaterial ink design to increase the bioactivity of hydrogels. However, besides the extraction of proteinous structures, the use of structurally intact FS as an additive could increase biocompatibility and bioactivity of hydrogels due to its organic (collagen) and inorganic (hydroxyapatite) contents, while simultaneously enhancing mechanical strength in three-dimensional (3D) printing applications. To test this hypothesis, we present here a composite biomaterial ink composed of FS and alginate dialdehyde (ADA)-GEL for 3D bioprinting applications. We fabricate 3D cell-laden hydrogels using mouse pre-osteoblast MC3T3-E1 cells. We evaluate the physicochemical and mechanical properties of FS incorporated ADA-GEL biomaterial inks as well as the bioactivity and cytocompatibility of cell-laden hydrogels. Due to the distinctive collagen orientation of the FS, the compressive strength of the hydrogels significantly increased with increasing FS particle content. Addition of FS also provided a tool to tune hydrogel stiffness. FS particles were homogeneously incorporated into the hydrogels. Particle-matrix integration was confirmed via scanning electron microscopy. FS incorporation in the ADA-GEL matrix increased the osteogenic differentiation of MC3T3-E1 cells in comparison to pristine ADA-GEL, as FS incorporation led to increased ALP activity and osteocalcin secretion of MC3T3-E1 cells. Due to the significantly increased stiffness and supported osteoinductivity of the hydrogels, FS structure as a natural collagen and hydroxyapatite source contributed to the biomaterial ink properties for bone engineering applications. Our findings indicate that ADA-GEL/FS represents a new biomaterial ink formulation with great potential for 3D bioprinting, and FS is confirmed as a promising additive for bone TE applications.

Preparation and In Vitro Characterization of Magnetic CS/PVA/HA/pSPIONs Scaffolds for Magnetic Hyperthermia and Bone Regeneration

Conventional bone cancer treatment often results in unwanted side effects, critical-sized bone defects, and inefficient cancer-cell targeting. Therefore, new approaches are necessary to better address bone cancer treatment and patient's recovery. One solution may reside in the combination of bone regeneration scaffolds with magnetic hyperthermia. By incorporating pristine superparamagnetic iron oxide nanoparticles (pSPIONs) into additively manufactured scaffolds we created magnetic structures for magnetic hyperthermia and bone regeneration. For this, hydroxyapatite (HA) particles were integrated in a polymeric matrix composed of chitosan (CS) and poly (vinyl alcohol) (PVA). Once optimized, pSPIONs were added to the CS/PVA/HA paste at three different concentrations (1.92, 3.77, and 5.54 wt.%), and subsequently additively manufactured to form a scaffold. Results indicate that scaffolds containing 3.77 and 5.54 wt.% of pSPIONs, attained temperature increases of 6.6 and 7.5 °C in magnetic hyperthermia testing, respectively. In vitro studies using human osteosarcoma Saos-2 cells indicated that pSPIONs incorporation significantly stimulated cell adhesion, proliferation and alkaline phosphatase (ALP) expression when compared to CS/PVA/HA scaffolds. Thus, these results support that CS/PVA/HA/pSPIONs scaffolds with pSPIONs concentrations above or equal to 3.77 wt.% have the potential to be used for magnetic hyperthermia and bone regeneration.

3D Printable Drug Delivery Systems: Next-generation Healthcare Technology and Regulatory Aspects

A revolutionary shift in healthcare has been sparked by the development of 3D printing, propelling us into an era replete with boundless opportunities for personalized DDS (Drug Delivery Systems). Precise control of the kinetics of drug release can be achieved through 3D printing, improving treatment efficacy and patient compliance. Additionally, 3D printing facilitates the co-administration of multiple drugs, simplifying treatment regimens. The technology offers rapid prototyping and manufacturing capabilities, reducing development timelines and costs. The seamless integration of advanced algorithms and artificial neural networks (ANN) augments the precision and efficacy of 3D printing, propelling us toward the forefront of personalized medicine. This comprehensive review delves into the regulatory frontiers governing 3D printable drug delivery systems, with an emphasis on adhering to rigorous safety protocols to ensure the well-being of patients by leveraging the latest advancements in 3D printing technologies powered by artificial intelligence. The paradigm promises superior therapeutic outcomes and optimized medication experiences and sets the stage for an immersive future within the Metaverse, wherein healthcare seamlessly converges with virtual environments to unlock unparalleled possibilities for personalized treatments.

Achievements in Mesoporous Bioactive Glasses for Biomedical Applications

Nowadays, mesoporous bioactive glasses (MBGs) are envisaged as promising candidates in the field of bioceramics for bone tissue regeneration. This is ascribed to their singular chemical composition, structural and textural properties and easy-to-functionalize surface, giving rise to accelerated bioactive responses and capacity for local drug delivery. Since their discovery at the beginning of the 21st century, pioneering research efforts focused on the design and fabrication of MBGs with optimal compositional, textural and structural properties to elicit superior bioactive behavior. The current trends conceive MBGs as multitherapy systems for the treatment of bone-related pathologies, emphasizing the need of fine-tuning surface functionalization. Herein, we focus on the recent developments in MBGs for biomedical applications. First, the role of MBGs in the design and fabrication of three-dimensional scaffolds that fulfil the highly demanding requirements for bone tissue engineering is outlined. The different approaches for developing multifunctional MBGs are overviewed, including the incorporation of therapeutic ions in the glass composition and the surface functionalization with zwitterionic moieties to prevent bacterial adhesion. The bourgeoning scientific literature on MBGs as local delivery systems of diverse therapeutic cargoes (osteogenic/antiosteoporotic, angiogenic, antibacterial, anti-inflammatory and antitumor agents) is addressed. Finally, the current challenges and future directions for the clinical translation of MBGs are discussed.

Three-Dimensional Bio-Printed Cardiac Patch for Sustained Delivery of Extracellular Vesicles from the Interface

Cardiac tissue engineering has emerged as a promising strategy to treat infarcted cardiac tissues by replacing the injured region with an ex vivo fabricated functional cardiac patch. Nevertheless, integration of the transplanted patch with the host tissue is still a burden, limiting its clinical application. Here, a bi-functional, 3D bio-printed cardiac patch (CP) design is proposed, composed of a cell-laden compartment at its core and an extracellular vesicle (EV)-laden compartment at its shell for better integration of the CP with the host tissue. Alginate-based bioink solutions were developed for each compartment and characterized rheologically, examined for printability and their effect on residing cells or EVs. The resulting 3D bio-printed CP was examined for its mechanical stiffness, showing an elastic modulus between 4-5 kPa at day 1 post-printing, suitable for transplantation. Affinity binding of EVs to alginate sulfate (AlgS) was validated, exhibiting dissociation constant values similar to those of EVs with heparin. The incorporation of AlgS-EVs complexes within the shell bioink sustained EV release from the CP, with 88% cumulative release compared with 92% without AlgS by day 4. AlgS also prolonged the release profile by an additional 2 days, lasting 11 days overall. This CP design comprises great potential at promoting more efficient patch assimilation with the host.

Height-to-Diameter Ratio and Porosity Strongly Influence Bulk Compressive Mechanical Properties of 3D-Printed Polymer Scaffolds

Although the architectural design parameters of 3D-printed polymer-based scaffolds-porosity, height-to-diameter (H/D) ratio and pore size-are significant determinants of their mechanical integrity, their impact has not been explicitly discussed when reporting bulk mechanical properties. Controlled architectures were designed by systematically varying porosity (30-75%, H/D ratio (0.5-2.0) and pore size (0.25-1.0 mm) and fabricated using fused filament fabrication technique. The influence of the three parameters on compressive mechanical properties-apparent elastic modulus E_app, bulk yield stress σ_y and yield strain ε_y-were investigated through a multiple linear regression analysis. H/D ratio and porosity exhibited strong influence on the mechanical behavior, resulting in variations in mean E_app of 60% and 95%, respectively. σ_y was comparatively less sensitive to H/D ratio over the range investigated in this study, with 15% variation in mean values. In contrast, porosity resulted in almost 100% variation in mean σ_y values. Pore size was not a significant factor for mechanical behavior, although it is a critical factor in the biological behavior of the scaffolds. Quantifying the influence of porosity, H/D ratio and pore size on bench-top tested bulk mechanical properties can help optimize the development of bone scaffolds from a biomechanical perspective.

Recent Developments in Additive-Manufactured Intermetallic Compounds for Bio-Implant Applications

Purpose

This paper reviews the recent developments of two newly developed intermetallic compounds (IMCs) of metallic glasses (MGs) and high-entropy alloys (HEAs) as potential implantable biomaterials.

Methods

The paper commences by summarizing the fundamental properties of recently developed MGs and high-entropy alloys (HEAs). A systematic review is presented of the recent literature about the use of AM technology in fabricating MG and HEA components for biological implant applications.

Results

The high strength, low Young’s modulus, and excellent corrosion resistance make these IMCs good candidates as bio-implantable materials. Recent studies have shown that additive manufacturing (AM) techniques provide an advantageous route for the preparation of glassy metallic components due to their intrinsically rapid cooling rates and ability to fabricate parts with virtually no size or complexity constraints. A practical example is conducted by AM producing a porous gradient Ti-based MG spinal cage. The produced MG powders and the in vivo test results on an 18 M-old Lanyu pig confirm the feasibility of the AM technique for producing implantable IMC-based prosthesis.

Conclusion

The non-crystalline structure of MGs alloy and the random crystalline composition of HEAs provide unique material properties that will substantially impact the development of future implantable prostheses.

Hybrid Ti6Al4V/Silk Fibroin Composite for Load-Bearing Implants: A Hierarchical Multifunctional Cellular Scaffold

Despite the tremendous technological advances that metal additive manufacturing (AM) has made in the last decades, there are still some major concerns guaranteeing its massive industrial application in the biomedical field. Indeed, some main limitations arise in dealing with their biological properties, specifically in terms of osseointegration. Morphological accuracy of sub-unital elements along with the printing resolution are major constraints in the design workspace of a lattice, hindering the possibility of manufacturing structures optimized for proper osteointegration. To overcome these issues, the authors developed a new hybrid multifunctional composite scaffold consisting of an AM Ti6Al4V lattice structure and a silk fibroin/gelatin foam. The composite was realized by combining laser powder bed fusion (L-PBF) of simple cubic lattice structures with foaming techniques. A combined process of foaming and electrodeposition has been also evaluated. The multifunctional scaffolds were characterized to evaluate their pore size, morphology, and distribution as well as their adhesion and behavior at the metal-polymer interface. Pull-out tests in dry and hydrated conditions were employed for the mechanical characterization. Additionally, a cytotoxicity assessment was performed to preliminarily evaluate their potential application in the biomedical field as load-bearing next-generation medical devices.

Additive Manufacturing of Biomaterials-Design Principles and Their Implementation

Additive manufacturing (AM, also known as 3D printing) is an advanced manufacturing technique that has enabled progress in the design and fabrication of customised or patient-specific (meta-)biomaterials and biomedical devices (e.g., implants, prosthetics, and orthotics) with complex internal microstructures and tuneable properties. In the past few decades, several design guidelines have been proposed for creating porous lattice structures, particularly for biomedical applications. Meanwhile, the capabilities of AM to fabricate a wide range of biomaterials, including metals and their alloys, polymers, and ceramics, have been exploited, offering unprecedented benefits to medical professionals and patients alike. In this review article, we provide an overview of the design principles that have been developed and used for the AM of biomaterials as well as those dealing with three major categories of biomaterials, i.e., metals (and their alloys), polymers, and ceramics. The design strategies can be categorised as: library-based design, topology optimisation, bio-inspired design, and meta-biomaterials. Recent developments related to the biomedical applications and fabrication methods of AM aimed at enhancing the quality of final 3D-printed biomaterials and improving their physical, mechanical, and biological characteristics are also highlighted. Finally, examples of 3D-printed biomaterials with tuned properties and functionalities are presented.

Advanced Biomaterials, Coatings, and Techniques: Applications in Medicine and Dentistry

The field of biomaterials is very extensive, encompassing both the materials themselves and the manufacturing methods, which are constantly developing [...]

Progress in manufacturing and processing of degradable Fe-based implants: a review

Biodegradable metals have gained vast attention as befitting candidates for developing degradable metallic implants. Such implants are primarily employed for temporary applications and are expected to degrade or resorbed after the tissue is healed. Fe-based materials have generated considerable interest as one of the possible biodegradable metals. Like other biometals such as Mg and Zn, Fe exhibits good biocompatibility and biodegradability. The versatility in the mechanical behaviour of Fe-based materials makes them a better choice for load-bearing applications. However, the very low degradation rate of Fe in the physiological environment needs to be improved to make it compatible with tissue growth. Several studies on tailoring the degradation behaviour of Fe in the human body are already reported. Majority of these works include studies on the effect of manufacturing and processing techniques on biocompatibility and biodegradability. This article focuses on a comprehensive review and analysis of the various manufacturing and processing techniques so far reported for developing biodegradable iron-based orthopaedic implants. The current status of research in the field is neatly presented, and a summary of the works is included in the article for the benefit of researchers in the field to contextualise their research and effectively find the lacunae in the existing scholarship.

Design and Implementation of Anatomically Inspired Mesenteric and Intestinal Vascular Patterns for Personalized 3D Bioprinting

Recent progress in bioprinting has made possible the creation of complex 3D intestinal constructs, including vascularized villi. However, for their integration into functional units useful for experimentation or implantation, the next challenge is to endow them with a larger-scale, anatomically realistic vasculature. In general, the perfusion of bioprinted constructs has remained difficult, and the current solution is to provide them with mostly linear and simply branched channels. To address this limitation, here we demonstrated an image analysis-based workflow leading through computer-assisted design from anatomic images of rodent mesentery and colon to the actual printing of such patterns with paste and hydrogel bioinks. Moreover, we reverse-engineered the 2D intestinal image-derived designs into cylindrical objects, and 3D-printed them in a support hydrogel. These results open the path towards generation of more realistically vascularized tissue constructs for a variety of personalized medicine applications.

Role of three-dimensional printing and artificial intelligence in the management of hepatocellular carcinoma: Challenges and opportunities

Hepatocellular carcinoma (HCC) constitutes the fifth most frequent malignancy worldwide and the third most frequent cause of cancer-related deaths. Currently, treatment selection is based on the stage of the disease. Emerging fields such as three-dimensional (3D) printing, 3D bioprinting, artificial intelligence (AI), and machine learning (ML) could lead to evidence-based, individualized management of HCC. In this review, we comprehensively report the current applications of 3D printing, 3D bioprinting, and AI/ML-based models in HCC management; we outline the significant challenges to the broad use of these novel technologies in the clinical setting with the goal of identifying means to overcome them, and finally, we discuss the opportunities that arise from these applications. Notably, regarding 3D printing and bioprinting-related challenges, we elaborate on cost and cost-effectiveness, cell sourcing, cell viability, safety, accessibility, regulation, and legal and ethical concerns. Similarly, regarding AI/ML-related challenges, we elaborate on intellectual property, liability, intrinsic biases, data protection, cybersecurity, ethical challenges, and transparency. Our findings show that AI and 3D printing applications in HCC management and healthcare, in general, are steadily expanding; thus, these technologies will be integrated into the clinical setting sooner or later. Therefore, we believe that physicians need to become familiar with these technologies and prepare to engage with them constructively.

Addition of High Acyl Gellan Gum to Low Acyl Gellan Gum Enables the Blends 3D Bioprintable

Long-term stability of gellan gum (GG) at physiological conditions is expected, as very low concentration of divalent ions are required for crosslinking, as compared to alginate—which is extensively used for tissue engineering (TE) applications. Hence, GG is proposed as an ideal candidate to substitute alginate for TE. Deacylated (low acyl; LA) GG forms brittle gels, thus only low concentrations were used for cell encapsulation, whereas acylated (high acyl; HA) GG forms weak/soft gels. 3D bioprinting using pure LAGG or HAGG is not possible owing to their rheological properties. Here, we report development and characterization of bioprintable blends of LAGG and HAGG. Increase in HAGG in the blends improved shear recovery and shape fidelity of printed scaffolds. Low volumetric swelling observed in cell culture conditions over 14 days indicates stability. Volumetric scaffolds were successfully printed and their mechanical properties were determined by uniaxial compressive testing. Mesenchymal stem cells bioprinted in blends of 3% LAGG and 3% HAGG survived the printing process showing >80% viability; a gradual decrease in cell numbers was observed over 21 days of culture. However, exploiting intrinsic advantages of 3D bioprinting, LAGG/HAGG blends open up numerous possibilities to improve and/or tailor various aspects required for TE.

Regenerating dynamic organs using biomimetic patches

The regeneration of dynamic organs remains challenging because they are intrinsically anisotropic and undergo large volumetric deformation during normal or pathological function. This hampers the durability and applicability of regenerative medicine approaches. To address the challenges of organ dynamics, a new class of patches have emerged with anisotropic and auxetic properties that mimic native tissue biomechanics and accommodate volumetric deformation. Here, we outline the critical design, materials, and processing considerations for achieving optimal patch biomechanics according to target pathology and summarize recent advances in biomimetic patches for dynamic organ regeneration. Furthermore, we discuss the challenges and opportunities which, if overcome, would open up new applications in organ regeneration and expedite the clinical translation of patch-based therapeutics.

Implication of Mesenchymal Stem Cells and Their Derivates for Osteochondral Regeneration

Healing of articular cartilage defects presents a challenging issue, due to its regenerative shortcomings. Lacking vascularity and innervation of cartilage and low proliferative potential of chondrocytes are the main reasons for the limited healing potential of articular cartilage. Traditional reparative approaches are limited in their efficiency, hence there is a demand for novel reparative treatments. Mesenchymal stromal cells, preferred for clinical uses, can be readily derived from various sources and have been proven to have a therapeutic effect on cartilage and subchondral bone. Therefore, mesenchymal stromal cells, their derivates, and scaffolds have been utilized in research targeting osteochondral regeneration. The present review aims to comprehensively outline and discuss literature considering this topic published within last 5 years.

3D-bioprinted peptide coupling patches for wound healing

Chronic wounds caused by severe trauma remain a serious challenge for clinical treatment. In this study, we developed a novel angiogenic 3D-bioprinted peptide patch to improve skin wound healing. The 3D-bioprinted technology can fabricate individual patches according to the shape characteristics of the damaged tissue. Gelatin methacryloyl (GelMA) and hyaluronic acid methacryloyl (HAMA) have excellent biocompatibility and biodegradability, and were used as a biomaterial to produce bioprinted patches. The pro-angiogenic QHREDGS peptide was covalently conjugated to the 3D-bioprinted GelMA/HAMA patches, extending the release of QHREDGS and improving the angiogenic properties of the patch. Our results demonstrated that these 3D-bioprinted peptide patches showed excellent biocompatibility, angiogenesis, and tissue repair both in vivo and in vitro. These findings indicated that 3D-bioprinted peptide patches improved skin wound healing and could be used in other tissue engineering applications.

Magnetism in Dentistry: Review and Future Perspectives

Tissue engineering or tissue reconstruction/repair/regeneration may be considered as a guiding strategy in oral and maxillofacial surgery, as well as in endodontics, orthodontics, periodontics, and daily clinical practice. A wide range of techniques has been developed over the past years, from tissue grafts to the more recent and innovative regenerative procedures. Continuous research in the field of natural and artificial materials and biomaterials, as well as in advanced scaffold design strategies has been carried out. The focus has also been on various growth factors involved in dental tissue repair or reconstruction. Benefiting from the recent literature, this review paper illustrates current innovative strategies and technological approaches in oral and maxillofacial tissue engineering, trying to offer some information regarding the available scientific data and practical applications. After introducing tissue engineering aspects, an overview on additive manufacturing technologies will be provided, with a focus on the applications of superparamagnetic iron oxide nanoparticles in the biomedical field. The potential applications of magnetic fields and magnetic devices on the acceleration of orthodontic tooth movement will be analysed.

Development of 3D Printed Smartphone-Based Multi-Purpose Fundus Camera (MultiScope) for Retinopathy of Prematurity

Retinopathy of Prematurity (ROP) is a prominent source of low vision and blindness in preterm babies. Wide-Field Digital Retinal Imaging (WFDRI) systems acquire accurate digital images which are very useful for identification, documentation and transmitting the various retinal diseases. This telemedicine technique has potential for an alternative tool for Binocular Indirect Ophthalmoscopy (BIO) in ROP screening, but it is very expensive and accessibility for poor communities is limited. Capabilities of good illumination, high resolution camera and processing speed of the modern smartphones are being identified as a substitute. Potential applications of 3D printing is that it provides a severe impact in medical field, especially in ophthalmology sector. Competences of 3D printing are very useful for the development of retinal camera from any smartphone with the help of 3D printable devices. The primary aim of this study is to develop a handheld 3D printed smartphone-based multi-purpose fundus camera for ROP screening. The secondary aim is to check the feasibility and compare the digital fundus images obtained from the developed fundus camera against the commercial RetCam imaging. The proposed cost effective and remote reading device is an alternative to WFDRI for ROP screening and can improve the potential of ROP care for low resource communities.