Assessing the efficacy of drugs on patient-derived 3D cell cultures, including spheroids, organoids, and bioprinted structures, enables crucial pre-clinical drug testing before patient use. These techniques empower us to choose the most appropriate pharmaceutical agent for the individual patient. Additionally, they promote improved recovery for patients, owing to the lack of time wasted in changing therapies. These models are suitable for both fundamental and practical research endeavors, given their treatment responses which closely resemble those of natural tissue. Furthermore, these methods, which are more budget-friendly and address the issues of interspecies variances, could potentially replace animal models in the future. Bioactive Compound Library chemical structure This review dissects this ever-shifting area of toxicological testing and its uses in practice.
The use of three-dimensional (3D) printing to create porous hydroxyapatite (HA) scaffolds provides broad application potential thanks to both the potential for personalized structural design and exceptional biocompatibility. Still, the absence of antimicrobial properties constricts its broad-scale use. In this study, a digital light processing (DLP) method was used to create a porous ceramic scaffold. Bioactive Compound Library chemical structure Scaffolds were treated with multilayer chitosan/alginate composite coatings, prepared using the layer-by-layer method, and zinc ions were crosslinked into the coatings through ionic incorporation. To ascertain the chemical composition and morphological features of the coatings, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were utilized. EDS analysis indicated a consistent and uniform distribution of Zn2+ within the coating material. Moreover, there was a slight improvement in the compressive strength of coated scaffolds (1152.03 MPa), in comparison to the compressive strength of the uncoated scaffolds (1042.056 MPa). In the soaking experiment, the degradation of the coated scaffolds occurred at a slower rate. Zinc-rich coatings, within specific concentration ranges, exhibited a heightened capacity, as shown by in vitro experiments, to foster cell adhesion, proliferation, and differentiation. Though Zn2+ over-release induced cytotoxicity, its antibacterial effectiveness was heightened against Escherichia coli (99.4%) and Staphylococcus aureus (93%).
Bone regeneration is significantly accelerated by the extensive adoption of light-based three-dimensional (3D) hydrogel printing techniques. However, the guiding principles behind traditional hydrogel creation disregard the biomimetic control mechanisms present during the multiple stages of bone healing, leading to hydrogels that are unable to sufficiently stimulate osteogenesis and consequently impede their efficacy in directing bone regeneration. Significant recent progress in synthetic biology-engineered DNA hydrogels offers the potential to improve current strategies, due to their advantages including resilience to enzymatic degradation, programmable characteristics, controllable structures, and valuable mechanical properties. However, the precise method of 3D printing DNA hydrogels is not clearly defined, emerging in a range of early experimental forms. This article offers a perspective on early 3D DNA hydrogel printing development, and proposes the potential use of hydrogel-based bone organoids in bone regeneration.
Multilayered biofunctional polymeric coatings are implemented on titanium alloy substrates using 3D printing techniques for surface modification. Polycaprolactone (PCL) and poly(lactic-co-glycolic) acid (PLGA) polymers were embedded with vancomycin (VA) for antibacterial activity and amorphous calcium phosphate (ACP) for osseointegration promotion, respectively. Compared to PLGA coatings, PCL coatings containing ACP displayed a consistent pattern of deposition and enhanced cell adhesion on titanium alloy substrates. By combining scanning electron microscopy and Fourier-transform infrared spectroscopy, a nanocomposite structure in ACP particles was observed, showcasing strong bonding with the polymers. Polymeric coatings demonstrated comparable MC3T3 osteoblast proliferation, as indicated by cell viability tests, equivalent to the positive control groups. Cell viability and death assessments, performed in vitro, indicated better cell adhesion on PCL coatings with 10 layers (experiencing a rapid ACP release) compared to PCL coatings with 20 layers (resulting in a sustained ACP release). The multilayered design and drug content of the PCL coatings, loaded with the antibacterial drug VA, determined the tunable release kinetics profile. Beyond this, the active VA concentration released from the coatings surpassed the minimum inhibitory and minimum bactericidal concentrations, indicating its efficacy in combating the Staphylococcus aureus bacterial strain. Developing antibacterial, biocompatible coatings to encourage bone growth around orthopedic implants is facilitated by this research.
In the field of orthopedics, the repair and rebuilding of bone defects continue to be substantial problems. Currently, a fresh and effective approach may be 3D-bioprinted active bone implants. Employing 3D bioprinting techniques, we produced customized active PCL/TCP/PRP scaffolds, layer by layer, in this case. The bioink was prepared from the patient's autologous platelet-rich plasma (PRP) and a polycaprolactone/tricalcium phosphate (PCL/TCP) composite scaffold material. Following the procedure to remove the tibial tumor, the scaffold was subsequently utilized within the patient to restore and reconstruct the bone. The clinical applications of 3D-bioprinted personalized active bone, differing from traditional bone implant materials, are substantial and stem from its inherent biological activity, osteoinductivity, and personalized design.
Three-dimensional bioprinting, a continually evolving technology, holds immense promise for revolutionizing regenerative medicine. Structures in bioengineering are fabricated by the additive deposition of biochemical products, biological materials, and living cells. For bioprinting, there exist numerous biomaterials and techniques, including various types of bioinks. The quality of these processes is contingent upon their rheological properties. The ionic crosslinking agent, CaCl2, was used in the preparation of alginate-based hydrogels in this study. Rheological characterization and simulations of bioprinting, performed under pre-determined conditions, were undertaken to search for potential correlations between rheological parameters and the bioprinting variables. Bioactive Compound Library chemical structure The extrusion pressure exhibited a clear linear relationship with the rheological parameter 'k' of the flow consistency index, while extrusion time similarly correlated linearly with the flow behavior index's rheological parameter 'n'. By streamlining the repetitive processes for optimizing extrusion pressure and dispensing head displacement speed in the dispensing head, the bioprinting procedure can utilize less material and time, improving the final results.
Large-scale skin injuries are frequently associated with compromised wound healing, leading to scar tissue development, and substantial health issues and fatalities. The purpose of this study is to investigate the in vivo application of 3D-printed tissue-engineered skin substitutes, incorporating human adipose-derived stem cells (hADSCs) within innovative biomaterials, for wound healing. Lyophilization and solubilization of extracellular matrix components from decellularized adipose tissue produced a pre-gel form of adipose tissue decellularized extracellular matrix (dECM). Composed of adipose tissue dECM pre-gel, methacrylated gelatin (GelMA), and methacrylated hyaluronic acid (HAMA), the newly designed biomaterial is a novel substance. Evaluation of the phase-transition temperature, together with the storage and loss moduli at this temperature, was achieved through rheological measurements. A 3D-printed skin substitute, reinforced with hADSCs, was developed from tissue engineering. We established a full-thickness skin wound healing model in nude mice, which were then randomly allocated into four groups: (A) a group receiving full-thickness skin grafts, (B) the 3D-bioprinted skin substitute group as the experimental group, (C) a microskin graft group, and (D) a control group. The decellularization criteria were satisfied as the DNA content in each milligram of dECM reached a concentration of 245.71 nanograms. The thermo-sensitive nature of the solubilized adipose tissue dECM resulted in a sol-gel phase transition with an increase in temperature. At a temperature of 175°C, the dECM-GelMA-HAMA precursor experiences a gel-sol phase transition, characterized by a storage and loss modulus of roughly 8 Pa. A suitable porosity and pore size 3D porous network structure was present in the interior of the crosslinked dECM-GelMA-HAMA hydrogel, as determined by scanning electron microscopy. Stability in the shape of the skin substitute is achieved through its regular, grid-like scaffold construction. Accelerated wound healing was observed in the experimental animals treated with the 3D-printed skin substitute, notably a lessening of the inflammatory response, increased blood flow near the wound, and promotion of re-epithelialization, collagen deposition and alignment, and new blood vessel formation. Overall, a 3D-printed skin substitute fabricated using dECM-GelMA-HAMA and infused with hADSCs effectively accelerates wound healing and enhances its quality through improved angiogenesis. The stable 3D-printed stereoscopic grid-like scaffold structure, in combination with hADSCs, is paramount in the acceleration of wound healing.
A novel 3D bioprinting system, including a screw-extrusion component, was created. The resulting polycaprolactone (PCL) grafts produced by screw-type and pneumatic pressure-type 3D bioprinters were then compared. By comparison, the screw-type printing method's single layers showed a 1407% increase in density and a 3476% rise in tensile strength in contrast to their pneumatic pressure-type counterparts. The screw-type bioprinter's PCL grafts showed a significant improvement in adhesive force (272 times), tensile strength (2989% greater), and bending strength (6776% higher) compared to those produced using the pneumatic pressure-type bioprinter.