3D printing is a smart additive manufacturing technique that allows the engineering of biomedical devices that are usually difficult to design using conventional methodologies such as machining or molding. Nowadays, 3D-printed microfluidics has gained enormous attention due to their various advantages including fast production, cost-effectiveness, and accurate designing of a range of products even geometrically complex devices. In this review, we focused on the recent significant findings in the field of 3D-printed microfluidic devices for biomedical applications. 3D printers are used as fabrication tools for a broad variety of systems for a range of applications like diagnostic microfluidic chips to detect different analytes, for example, glucose, lactate, and glutamate and the biomarkers related to different clinically relevant diseases, for example, malaria, prostate cancer, and breast cancer. 3D printers can print various materials (inorganic and polymers) with varying density, strength, and chemical properties that provide users with a broad variety of strategic options. In this article, we have discussed potential 3D printing techniques for the fabrication of microfluidic devices that are suitable for biomedical applications. Emerging diagnostic technologies using 3D printing as a method for integrating living cells or biomaterials into 3D printing are also reviewed.

Aloe vera (AV) and tetracycline hydrochloride (TCH) exhibit significant properties such as anti-inflammatory, antioxidant and anti-bacterial activities to facilitate skin tissue engineering. The present study aims to develop poly-ε-caprolactone (PCL)/ AV containing curcumin (CUR), and TCH loaded hybrid nanofibrous scaffolds to validate the synergistic effect on the fibroblast proliferation and antimicrobial activity against Gram-positive and Gram-negative bacteria for wound healing. PCL/AV, PCL/CUR, PCL/AV/CUR and PCL/AV/TCH hybrid nanofibrous mats were fabricated using an electrospinning technique and were characterized for surface morphology, the successful incorporation of active compounds, hydrophilicity and the mechanical property of nanofibers. SEM revealed that there was a decrease in the fiber diameter (ranging from 360 to 770 nm) upon the addition of AV, CUR and TCH in PCL nanofibers, which were randomly oriented with bead free morphology. FTIR spectra of various electrospun samples confirmed the successful incorporation of AV, CUR and TCH into the PCL nanofibers. The fabricated nanofibrous scaffolds possessed mechanical properties within the range of human skin. The biocompatibility of electrospun nanofibrous scaffolds were evaluated on primary human dermal fibroblasts (hDF) by MTS assay, CMFDA, Sirius red and F-actin stainings. The results showed that the fabricated PCL/AV/CUR and PCL/AV/TCH nanofibrous scaffolds were non-toxic and had the potential for wound healing applications. The disc diffusion assay confirmed that the electrospun nanofibrous scaffolds possessed antibacterial activity and provided an effective wound dressing for skin tissue engineering.

The progress and the fundamental mechanisms for field emission of diverse carbon materials with dimensions 3D–0D, and the future prospects are comprehensively discussed.