Bioprinting technology has emerged as an important approach to bone and cartilage tissue engineering applications, because it allows the printing of scaffolds loaded with various components, such as cells, growth factors, or drugs. In this context, the bone has a very complex architecture containing highly vascularized and calcified tissues, while cartilage is avascular and has low cellularity and few nutrients. Owing to this complexity, the repair and regeneration of these tissues are highly challenging. Identification of the appropriate biomaterial and fabrication technologies can provide sustainable solutions to this challenge. Here, nanosized Laponite® (Laponite is a trademark of the company BYK Additives Ltd.) has shown to be a promising material due to its unique properties such as excellent biocompatibility, facile gel formation, shear‐thinning property (reversible physical crosslinking), high specific surface area, degrade into nontoxic products, and with osteoinductive properties. Even though Laponite and Laponite‐based composite for 3D bioprinting application are considered as soft gels, they may therefore not be thought exhibiting sufficient mechanical strength for orthopedic applications. However, through the merging with suitable composite and, also by incorporation of crosslinking step, desired mechanical strength for orthopedic application can be obtained. In this review, recent advances and future perspective of bioprinting Laponite and Laponite composites for orthopedic applications are highlighted.

Poly (lactic acid) (PLA) has been increasingly used in cutaneous tissue engineering due to its low cost, ease of handling, biodegradability, and biocompatibility, as well as its ability to form composites. However, these polymers possess a structure with nanoporous that mimic the cellular environment. In this study, nanocomposites are prepared using PLA and titanium dioxide (TiO 2) (10 and 35%-w/w) nanoparticles that also function as an active anti-scarring agent. The nanocomposites were prepared using an electrospinning technique. Three different solutions were prepared as follows: PLA, 10% PLA/TiO 2 , and 35% PLA/TiO 2 (w/w%). Electrospun PLA and PLA/TiO 2 nanocomposites were characterized morphologically, structurally, and chemically using electron scanning microscopy, transmission electron microscopy, goniometry, and X-ray diffraction. L929 fibroblast cells were used for in vitro tests. The cytotoxic effect was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays. Versicam (VCAN), biglicam (BIG), interleukin-6 (IL6), interleukin-10 (IL-10), and type-1 collagen (COL1A1) genes were evaluated by RT-qPCR. In vivo tests using Wistar rats were conducted for up to 15 days. Nanofibrous fibers were obtained for all groups that did not contain residual solvents. No cytotoxic effects were observed for up to 168 h. The genes expressed showed the highest values of versican and collagen-1 (p < 0.05) for PLA/TiO 2 nanocomposite scaffolds when compared to the control group (cells). Histological images showed that PLA at 10 and 35% w/w led to a discrete inflammatory infiltration and expression of many newly formed vessels, indicating increased metabolic activity of this tissue. To summarize, this study supported the potential of PLA/TiO 2 nanocomposites ability to reduce cutaneous scarring in scaffolds.

The chemical modification of porous ceramic scaffold surfaces with calcium phosphate surges as an alternative to improve the bioactivity to be used as bone grafts. The biomimetic method has been commonly used to modify surfaces of Ti alloys but surges as alternative to modify ceramic biomaterials. Herein, we modified the surface of Al 2 O 3 scaffolds with calcium phosphate minerals and strontium using the biomimetic method. The scaffolds were chemically treated using H 3 PO 4 solution and then immersed in simulated body fluid 5× solution for 14 days. For the incorporation of strontium, they were immersed in an aqueous solution of 100 ppm analytical-grade Sr(NO 3 ) 2 under magnetic stirring. The samples were characterized by scanning electron microscopy, X-ray microtomography, X-ray diffraction, near-infrared spectroscopy, inductively coupled plasma emission spectroscopy, and energy-dispersive X-ray spectroscopy. The biocompatibility and ability to differentiate osteoblasts in vitro were evaluated using human cells. The incorporation of strontium into the phosphate structure was verified. Scaffolds were obtained with high porosity, three-dimensional structures, and the preferential adhesion and maturation of osteoblastic cells, which are essential to promote bone regeneration in vivo. K E Y W O R D Sbioactivity, calcium phosphate, scaffolds, surface modification

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