Alginate Bioink Research Articles

Insights on the role of cryoprotectants in enhancing the properties of bioinks required for cryobioprinting of biological constructs

Preservation and long-term storage of readily available cell-laden tissue-engineered products are major challenges in expanding their applications in healthcare. In recent years, there has been increasing interest in the development of off-the-shelf tissue-engineered products using the cryobioprinting approach. Here, bioinks are incorporated with cryoprotective agents (CPAs) to allow the fabrication of cryopreservable tissue constructs. Although this method has shown potential in the fabrication of cryopreservable tissue-engineered products, the impact of the CPAs on the viscoelastic behavior and printability of the bioinks at cryo conditions remains unexplored. In this study, we have evaluated the influence of CPAs such as glycerol and dimethyl sulfoxide (DMSO) on the rheological properties of pre-crosslinked alginate bioinks for cryoprinting applications. DMSO-incorporated bioinks showed a reduction in viscosity and yield stress, while the addition of glycerol improved both the properties due to interactions with the calcium chloride used for pre-crosslinking. Further, tube inversion and printability experiments were performed to identify suitable concentrations and cryobioprinting conditions for bioinks containing CPAs & pre-crosslinked with CaCl2. Finally, based on the printability analysis & cell recovery results, 10% glycerol was used for cryobioprinting and preservation of cell-laden constructs at −80 °C and the viability of cells within the printed structures were evaluated after recovery. Cell viability results indicate that the addition of 10% glycerol to the pre-crosslinked bioink significantly improved cell viability compared to bioinks without CPAs, confirming the suitability of the developed bioink combination to fabricate tissue constructs for on-demand applications.Graphical abstractEffect of cryoprotectants on the viscoelastic behavior of bioinks and cell recovery in cryobioprinted tissue constructs.

Improved alginate bio-ink by recombinant self-assembled cell-sized spider-silk inspired-biopolymer

Improved alginate bio-ink by recombinant self-assembled cell-sized spider-silk inspired-biopolymer

A coaxial 3D bioprinted hybrid vascular scaffold based on decellularized extracellular matrix/nano clay/sodium alginate bioink.

Currently, vascular grafting is the preferred option to replace or bypass the defective vascular segments, but finding materials with good biocompatibility and diversity alternative for practical clinical applications are still the challenge. The construction of tissue engineered blood vessels (TEBVs) with complex structures will be realized using 3D bioprinting technology, which provides a new idea for vascular transplantation. In this paper, the decellularized extracellular matrix (dECM)/nano clay (NC)/sodium alginate (SA) hybrid bioink was prepared to construct tubular scaffolds in vitro by coaxial 3D bioprinting. The physical properties of the tubular scaffolds showed that there were plenty of pores, of which the size was ranged from 5 μm to 100 μm. Among them, the 2d/NC/SA scaffold not only has good hydrophilicity (>300 %), good biomechanical properties (tensile strength: 0.99 ± 0.01 MPa, Young's modulus: 0.61 ± 0.02 MPa) and low hemolysis ratio (0.3 %), but also can effectively enhance cell adhesion and proliferation. Cell experiment also showed that the cell density and cell colonies were large and more on the coaxial printed tubular scaffolds compare to those on the 3D printed lamellar scaffolds, and the 2d/NC/SA tubular scaffold has the best bioactivity of tunica intima model. Overall, the advanced dECM/NC/SA tubular scaffold has a considerable potential to be applied in vascular tissue engineering.

Influence of Hydroxyapatite and Gelatin Content on Crosslinking Dynamics and HDFn Cell Viability in Alginate Bioinks for 3D Bioprinting.

This study investigates how varying concentrations of hydroxyapatite (OHAp) and the addition of gelatin influence the ionic crosslinking time of alginate-based bioinks, as well as the shear stress experienced by neonatal human dermal fibroblasts (HDFn) during extrusion. These factors are crucial for validating bioinks and developing viable 3D bioprinted models. Four bioink formulations were created with a 50/50 ratio of alginate to gelatin, incorporating different calcium phosphate concentrations (0%, 1%, 5%, and 10%). The bioink compositions were confirmed via Fourier Transform Infrared (FT-IR) spectroscopy, and rheological analyses evaluated their pseudoplastic behavior, printability limits, and crosslinking times. The results indicated a notable increase in the consistency index (k) from 0.32 for the 0% OHAp formulation to 0.48 for the 10% OHAp formulation, suggesting improved viscoelastic properties. The elastic modulus recovery after crosslinking rose significantly from 245 Pa to 455 Pa. HDFn experienced a shear stress of up to 1.5436 Pa at the tip during extrusion with the HDFn-ALG5-GEL5-OHAp10 bioinks, calculated at a shear rate as low as 2 s-1. Viability assays confirmed over 70% cell viability 24 h post-extrusion and 92% viability after 7 days for the 10% OHAp formulation, highlighting the potential of hydroxyapatite-enhanced bioinks in tissue engineering applications.

Design and Characterization of Biomimetic Hybrid Construct Based on Hyaluronic Acid and Alginate Bioink for Regeneration of Articular Cartilage.

Background/Objectives: Three-dimensional bioprinting technology has enabled great advances in the treatment of articular cartilage (AC) defects by the biofabrication of biomimetic constructs that restore and/or regenerate damaged tissue. In this sense, the selection of suitable cells and biomaterials to bioprint constructs that mimic the architecture, composition, and functionality of the natural extracellular matrix (ECM) of the native tissue is crucial. In the present study, a novel cartilage-like biomimetic hybrid construct (CBC) was developed by 3D bioprinting to facilitate and promote AC regeneration. Methods: The CBC was biofabricated by the co-bioprinting of a bioink based on hyaluronic acid (HA) and alginate (AL) loaded with human mesenchymal stromal cells (hMSCs), with polylactic acid supporting the biomaterial, in order to mimic the microenvironment and structural properties of native AC, respectively. The CBC was biologically in vitro characterized. In addition, its physiochemical characteristics were evaluated in order to determine if the presence of hMSCs modified its properties. Results: Results from biological analysis demonstrated that CBC supported the high viability and proliferation of hMSCs, facilitating chondrogenesis after 5 weeks in vitro. The evaluation of physicochemical properties in the CBCs confirmed that the CBC developed could be suitable for use in cartilage tissue engineering. Conclusions: The results demonstrated that the use of bioprinted CBCs based on hMSC-AL/HA-bioink for AC repair could enhance the regeneration and/or formation of hyaline cartilaginous tissue.

Remote-Controlled Gene Delivery in Coaxial 3D-Bioprinted Constructs using Ultrasound-Responsive Bioinks

IntroductionCoaxial 3D bioprinting has advanced the formation of tissue constructs that recapitulate key architectures and biophysical parameters for in-vitro disease modeling and tissue-engineered therapies. Controlling gene expression within these structures is critical for modulating cell signaling and probing cell behavior. However, current transfection strategies are limited in spatiotemporal control because dense 3D scaffolds hinder diffusion of traditional vectors. To address this, we developed a coaxial extrusion 3D bioprinting technique using ultrasound-responsive gene delivery bioinks. These bioink materials incorporate echogenic microbubble gene delivery particles that upon ultrasound exposure can sonoporate cells within the construct, facilitating controllable transfection.MethodsPhospholipid-coated gas-core microbubbles were electrostatically coupled to reporter transgene plasmid payloads and incorporated into cell-laden alginate bioinks at varying particle concentrations. These bioinks were loaded into the coaxial nozzle core for extrusion bioprinting with CaCl2 crosslinker in the outer sheath. Resulting bioprints were exposed to 2.25 MHz focused ultrasound and evaluated for microbubble activation and subsequent DNA delivery and transgene expression.ResultsCoaxial printing parameters were established that preserved the stability of ultrasound-responsive gene delivery particles for at least 48 h in bioprinted alginate filaments while maintaining high cell viability. Successful sonoporation of embedded cells resulted in DNA delivery and robust ultrasound-controlled transgene expression. The number of transfected cells was modulated by varying the number of focused ultrasound pulses applied. The size region over which DNA was delivered was modulated by varying the concentration of microbubbles in the printed filaments.ConclusionsOur results present a successful coaxial 3D bioprinting technique designed to facilitate ultrasound-controlled gene delivery. This platform enables remote, spatiotemporally-defined genetic manipulation in coaxially bioprinted tissue constructs with important applications for disease modeling and regenerative medicine.

Composite bioink incorporating cell-laden liver decellularized extracellular matrix for bioprinting of scaffolds for bone tissue engineering

The field of bone tissue engineering (BTE) has witnessed a revolutionary breakthrough with the advent of three-dimensional (3D) bioprinting technology, which is considered an ideal choice for constructing scaffolds for bone regeneration. The key to realizing scaffold biofunctions is the selection and design of an appropriate bioink, and existing bioinks have significant limitations. In this study, a composite bioink based on natural polymers (gelatin and alginate) and liver decellularized extracellular matrix (LdECM) was developed and used to fabricate scaffolds for BTE using 3D bioprinting. Through in vitro studies, the concentration of LdECM incorporated into the bioink was optimized to achieve printability and stability and to improve the proliferation and osteogenic differentiation of loaded rat bone mesenchymal stem cells (rBMSCs). Furthermore, in vivo experiments were conducted using a Sprague Dawley rat model of critical-sized calvarial defects. The proposed rBMSC-laden LdECM–gelatin–alginate scaffold, bioprinted layer-by-layer, was implanted in the rat calvarial defect and the development of new bone growth was studied for four weeks. The findings showed that the proposed bioactive scaffolds facilitated angiogenesis and osteogenesis at the defect site. The findings of this study suggest that the developed rBMSC-laden LdECM–gelatin–alginate bioink has great potential for clinical translation and application in solving bone regeneration problems.

Experimental Study on Compatibility of Human Bronchial Epithelial Cells in Collagen-Alginate Bioink for 3D Printing.

This paper reports an experimental study on the compatibility of human bronchial epithelial (HBE) cells in a collagen-alginate bioink. The compatibility was assessed using the culture well method with three bioink compositions prepared from a 10% alginate solution and neutralized TeloCol-10 mg/mL collagen stock solution. Cell viability, quantified by (live cell count-dead cell count)/live cell count within the HBE cell-laden hydrogel, was evaluated using the live/dead assay method from Day 0 to Day 6. Experimental results demonstrated that the collagen-alginate 4:1 bioink composition exhibited the highest cell viability on Day 6 (85%), outperforming the collagen-alginate 1:4 bioink composition and the alginate bioink composition, which showed cell viability of 75% and 45%, respectively. Additionally, the live cell count was highest for the collagen-alginate 4:1 bioink composition on Day 0, a trend that persisted through Days 1 to 6, underscoring its superior performance in maintaining cell viability and promoting cell proliferation. These findings show that the compatibility of HBE cells with the collagen-alginate 4:1 bioink composition was higher compared with the other two bioink compositions.

Using 3D-bioprinted models to study pediatric neural crest-derived tumors.

The use of three-dimensional (3D) bioprinting has remained at the forefront of tissue engineering and has recently been employed for generating bioprinted solid tumors to be used as cancer models to test therapeutics. In pediatrics, neural crest-derived tumors are the most common type of extracranial solid tumors. There are only a few tumor-specific therapies that directly target these tumors, and the lack of new therapies remains detrimental to improving the outcomes for these patients. The absence of more efficacious therapies for pediatric solid tumors, in general, may be due to the inability of the currently employed preclinical models to recapitulate the solid tumor phenotype. In this study, we utilized 3D bioprinting to generate neural crest-derived solid tumors. The bioprinted tumors consisted of cells from established cell lines and patient-derived xenograft tumors mixed with a 6% gelatin/1% sodium alginate bioink. The viability and morphology of the bioprints were analyzed via bioluminescence and immunohisto chemistry, respectively. We compared the bioprints to traditional twodimensional (2D) cell culture under conditions such as hypoxia and therapeutics. We successfully produced viable neural crest-derived tumors that retained the histology and immunostaining characteristics of the original parent tumors. The bioprinted tumors propagated in culture and grew in orthotopic murine models. Furthermore, compared to cells grown in traditional 2D culture, the bioprinted tumors were resistant to hypoxia and chemotherapeutics, suggesting that the bioprints exhibited a phenotype that is consistent with that seen clinically in solid tumors, thus potentially making this model superior to traditional 2D culture for preclinical investigations. Future applications of this technology entail the potential to rapidly print pediatric solid tumors for use in high-throughput drug studies, expediting the identification of novel, individualized therapies.

A customized extrusion-based 3D bioprinter applied for muscle cell-laden nanocellulose alginate bioink

A customized extrusion-based 3D bioprinter applied for muscle cell-laden nanocellulose alginate bioink

Innovative thermosensitive alginate bioink combining cations for enhanced 3D extrusion bioprinting for tissue engineering

Sodium alginate (SA) hydrogels are widely used in 3D extrusion bioprinting, but their isolated use does not meet all the requirements for this application. To overcome this problem, crosslinking with divalent cations and combinations with other polymers, such as gelatin (Gel), are employed to improve their mechanical performance and bioactivity. In this study, we proposed a new concept of pre-crosslinking SA and SA/Gel inks with divalent cations Ca2+, Co2+, and Zn2+ and their binary mixtures. These inks were successfully formulated and characterized, and it was observed that different ion ratios can impart essential characteristics and properties for 3D extrusion bioprinting. To evaluate the thermosensitive response of these inks, it was included gelatin in a dispersed phase, giving the 3D-printed system a 4D character. The hydrogel with the best mechanical and biological performance was the pre-crosslinked composition with mixtures of divalent Ca2+/Co2+ ions, whereas it was observed through the live/dead assay that the presence of Zn2+ ions in the hydrogels on day 3 reduced the cell viability. This composition was used to develop a bioink for 4D printing using cell spheroid or single cells, with spheroids presenting better viability after 7 days than single cells. These results emphasize the importance of obtaining a pre-crosslinked bioink with modulated properties by employing divalent ions for 4D biofabrication and that 3D cell culture ensures superior resistance to 3D extrusion bioprinting when compared to single cells. Those characteristics give us an interesting bioink with high potential to be used in regenerative medicine of soft tissues.

Skeletal Muscle Spheroids as Building Blocks for Engineered Muscle Tissue.

Spheroids exhibit enhanced cell-cell interactions that facilitate improved survival and mimic the physiological cellular environment in vivo. Cell spheroids have been successfully used as building blocks for engineered tissues, yet the viability of this approach with skeletal muscle spheroids is poorly understood, particularly when incorporated into three-dimensional (3D) constructs. Bioprinting is a promising strategy to recapitulate the hierarchical organization of native tissue that is fundamental to its function. However, the influence of bioprinting on skeletal muscle cell spheroids and their function are yet to be interrogated. Using C2C12 mouse myoblasts and primary bovine muscle stem cells (MuSCs), we characterized spheroid formation as a function of duration and cell seeding density. We then investigated the potential of skeletal muscle spheroids entrapped in alginate bioink as tissue building blocks for bioprinting myogenic tissue. Both C2C12 and primary bovine MuSCs formed spheroids of similar sizes and remained viable after bioprinting. Spheroids of both cell types fused into larger tissue clusters over time within alginate and exhibited tissue formation comparable to monodisperse cells. Compared to monodisperse cells in alginate gels, C2C12 spheroids exhibited greater MyHC expression after 2 weeks, while cells within bovine MuSC spheroids displayed increased cell spreading. Both monodisperse and MuSC spheroids exhibited increased expression of genes denoting mid- and late-stage myogenic differentiation. Together, these data suggest that skeletal muscle spheroids have the potential for generating myogenic tissue via 3D bioprinting and reveal areas of research that could enhance myogenesis and myogenic differentiation in future studies.

Increasing Collagen to Bioink Drives Mesenchymal Stromal Cells-Chondrogenesis from Hyaline to Calcified Layers.

The bioextrusion of mesenchymal stromal cells (MSCs) directly seeded in a bioink enables the production of three-dimensional (3D) constructs, promoting their chondrogenic differentiation. Our study aimed to evaluate the effect of different type I collagen concentrations in the bioink on MSCs' chondrogenic differentiation. We printed 3D constructs using an alginate, gelatin, and fibrinogen-based bioink cellularized with MSCs, with four different quantities of type I collagen addition (0.0, 0.5, 1.0, and 5.0 mg per bioink syringe). We assessed the influence of the bioprinting process, the bioink composition, and the growth factor (TGF-ꞵ1) on the MSCs' survival rate. We confirmed the biocompatibility of the process and the bioinks' cytocompatibility. We evaluated the chondrogenic effects of TGF-ꞵ1 and collagen addition on the MSCs' chondrogenic properties through macroscopic observation, shrinking ratio, reverse transcription polymerase chain reaction, glycosaminoglycan synthesis, histology, and type II collagen immunohistochemistry. The bioink containing 0.5 mg of collagen produces the richest hyaline-like extracellular matrix, presenting itself as a promising tool to recreate the superficial layer of hyaline cartilage. The bioink containing 5.0 mg of collagen enhances the synthesis of a calcified matrix, making it a good candidate for mimicking the calcified cartilaginous layer. Type I collagen thus allows the dose-dependent design of specific hyaline cartilage layers.

Three-Dimensional Bioprinting in Soft Tissue Engineering for Plastic and Reconstructive Surgery.

Skeletal muscle tissue engineering (TE) and adipose tissue engineering have undergone significant progress in recent years. This review focuses on the key findings in these areas, particularly highlighting the integration of 3D bioprinting techniques to overcome challenges and enhance tissue regeneration. In skeletal muscle TE, 3D bioprinting enables the precise replication of muscle architecture. This addresses the need for the parallel alignment of cells and proper innervation. Satellite cells (SCs) and mesenchymal stem cells (MSCs) have been utilized, along with co-cultivation strategies for vascularization and innervation. Therefore, various printing methods and materials, including decellularized extracellular matrix (dECM), have been explored. Similarly, in adipose tissue engineering, 3D bioprinting has been employed to overcome the challenge of vascularization; addressing this challenge is vital for graft survival. Decellularized adipose tissue and biomimetic scaffolds have been used as biological inks, along with adipose-derived stem cells (ADSCs), to enhance graft survival. The integration of dECM and alginate bioinks has demonstrated improved adipocyte maturation and differentiation. These findings highlight the potential of 3D bioprinting techniques in skeletal muscle and adipose tissue engineering. By integrating specific cell types, biomaterials, and printing methods, significant progress has been made in tissue regeneration. However, challenges such as fabricating larger constructs, translating findings to human models, and obtaining regulatory approvals for cellular therapies remain to be addressed. Nonetheless, these advancements underscore the transformative impact of 3D bioprinting in tissue engineering research and its potential for future clinical applications.

3D Bioprinting of Acellular Corneal Stromal Scaffolds with a Low Cost Modified 3D Printer: A Feasibility Study

Purpose Loss of corneal transparency is one of the major causes of visual loss, generating a considerable health and economic burden globally. Corneal transplantation is the leading treatment procedure, where the diseased cornea is replaced by donated corneal tissue. Despite the rise of cornea donations in the past decade, there is still a huge gap between cornea supply and demand worldwide. 3D bioprinting is an emerging technology that can be used to fabricate tissue equivalents that resemble the native tissue, which holds great potential for corneal tissue engineering application. This study evaluates the manufacturability of 3D bioprinted acellular corneal grafts using low-cost equipment and software, not necessarily designed for bioprinting applications. This approach allows access to 3D printed structures where commercial 3D bioprinters are cost prohibitive and not readily accessible to researchers and clinicians. Methods Two extrusion-based methods were used to 3D print acellular corneal stromal scaffolds with collagen, alginate, and alginate-gelatin composite bioinks from a digital corneal model. Compression testing was used to determine moduli. Results The printed model was visually transparent with tunable mechanical properties. The model had central radius of curvature of 7.4 mm, diameter of 13.2 mm, and central thickness of 0.4 mm. The compressive secant modulus of the material was 23.7 ± 1.7 kPa at 20% strain. 3D printing into a concave mold had reliability advantages over printing into a convex mold. Conclusions The printed corneal models exhibited visible transparency and a dome shape, demonstrating the potential of this process for the preparation of acellular partial thickness corneal replacements. The modified printing process presented a low-cost option for corneal bioprinting.

Advantage of Alginate Bioinks in Biofabrication for Various Tissue Engineering Applications

Bioprinting is fast emerging as a viable technique for organ fabrication. Though various types of bioprinting methods have been developed, the most commonly used bioprinting is extrusion-based bioprinting (EBB). Bioinks are extruded layer-by-layer forming a 3D multicellular construct and scaled up to dimensions depending upon the specific tissue to be regenerated. Among various bioinks, alginate, a natural polysaccharide, has been extensively used because of its good printability in physiologically amenable conditions. Though alginate possesses good printability properties, it promotes little cell–material interaction resulting in limited biofunctionality. Therefore, it becomes necessary to blend/modify alginate to improve the biological properties of bioink without compromising printability. This paper presents a review of the various approaches used to optimize bioprinting with alginate bioinks and their limitations.

Internally crosslinked alginate-based bioinks for the fabrication of in vitro hepatic tissue models

Bioprinting is a key technique to fabricate cell-laden volumetric constructs with controlled geometry. It can be used not only to replicate the architecture of a target organ but also to produce shapes that allow for the mimicry, in vitro, of specific desired features. Among the various materials suitable to be processed with this technique, sodium alginate is currently considered one of the most appealing because of its versatility. To date, the most widespread strategies to print alginate-based bioinks exploit external gelation as a primary process, by directly extruding the hydrogel-precursor solution into a crosslinking bath or within a sacrificial crosslinking hydrogel, where the gelation takes place. In this work, we describe the print optimization and the processing of Hep3Gel: an internally crosslinked alginate and ECM-based bioink for the production of volumetric hepatic tissue models. We adopted an unconventional strategy, by moving from the reproduction of the geometry and the architecture of liver tissue to the use of bioprinting to fabricate structures that can promote a high degree of oxygenation, as is the case with hepatic tissue. To this end, the design of structures was optimized by employing computational methods. The printability of the bioink was then studied and optimized through a combination of different a priori and a posteriori analyses. We produced 14-layered constructs, thus highlighting the possibility to exploit internal gelation alone to directly print self-standing structures with finely controlled viscoelastic properties. Constructs loaded with HepG2 cells were successfully printed and cultured in static conditions for up to 12 d, underlining the suitability of Hep3Gel to support mid/long-term cultures.

3D printed hydrogel scaffold promotes the formation of hormone-active engineered parathyroid tissue

The parathyroid glands are localized at the back of the thyroid glands in the cervical region and are responsible for regulation of the calcium level in the blood, through specialized cells that sense Ca2+ and secrete parathyroid hormone (PTH) in response to a decline in its serum level. PTH stimulates the skeleton, kidneys and intestines and controls the level of Ca2+ through specialized activities. Iatrogenic removal of the parathyroid gland, as well as damage to its vascular integrity during cauterization are some of the common complications of thyroid surgery. Therefore, regeneration and/or replacement of malfunctioning parathyroid tissue is required. Tissue engineering is an emerging and promising field for patients with organ failure with recent pioneering clinical applications. The success of tissue engineering strategy depends on the use of proper cells, bioactive factors that stimulate the activities of these cells and scaffolds that are produced to recapitulate the tissue structure and support the function of the engineered tissues. 3D printing is a developing strategy for the production of these scaffolds by providing a delicate control over their structure and properties. In this study, human primary parathyroid cells were successfully isolated and their viability and ability to secrete PTH upon stimulation with different levels of Ca2+ were shown in vitro. These cells were then seeded onto 3D printed alginate scaffolds and 3D bioprinted within alginate bioink, and cell viability as well as the ability to secrete PTH upon stimulation were also demonstrated. Therefore, functional hormone-active parathyroid tissue substitute was engineered in vitro through 3D printed hydrogels and autologous cells.

Three-Dimensional Bioprinting of an In Vitro Lung Model.

In December 2019, COVID-19 emerged in China, and in January 2020, the World Health Organization declared a state of international emergency. Within this context, there is a significant search for new drugs to fight the disease and a need for in vitro models for preclinical drug tests. This study aims to develop a 3D lung model. For the execution, Wharton's jelly mesenchymal stem cells (WJ-MSC) were isolated and characterized through flow cytometry and trilineage differentiation. For pulmonary differentiation, the cells were seeded in plates coated with natural functional biopolymer matrix as membrane until spheroid formation, and then the spheroids were cultured with differentiation inductors. The differentiated cells were characterized using immunocytochemistry and RT-PCR, confirming the presence of alveolar type I and II, ciliated, and goblet cells. Then, 3D bioprinting was performed with a sodium alginate and gelatin bioink in an extrusion-based 3D printer. The 3D structure was analyzed, confirming cell viability with a live/dead assay and the expression of lung markers with immunocytochemistry. The results showed that the differentiation of WJ-MSC into lung cells was successful, as well as the bioprinting of these cells in a 3D structure, a promising alternative for in vitro drug testing.

Extrusion of Cell Encapsulated in Boron Nitride Nanotubes Reinforced Gelatin-Alginate Bioink for 3D Bioprinting.

Three-dimensional (3D) bioprinting, an innovative technology, has gained the attention of researchers as a promising technique for the redevelopment of complex tissue or organ structures. Despite significant advancements, a major challenge in 3D bioprinting is the limited number of suitable bioinks that fulfil the physiochemical requirements to produce complicated structures. Therefore, there is a demand for the production of bioinks for 3D bioprinting techniques. In this short communication, THP-1 cells encapsulated in boron nitride nanotubes (BNNTs) reinforced gelatin and alginate bioink was prepared. The study investigated the impact on the cells during printing using a fluorescence cell image. The results showed that the pure polymer bioinks demonstrated poor printability properties with the incorporation of cells. However, BNNT-combined bioink showed a significant increase in structural integrity even after the incorporation of cells. Furthermore, the scaffold structure was successfully printed with the cells incorporated bioink, and a considerable number of live cells were observed. With further studies, BNNTs as a promising nanomaterial for formulating bioink encapsulated with cells can be understood fully.