Angiogenesis is an important process in tissue repair and regeneration as blood vessels are integral to supply nutrients to a functioning tissue. In this review, the application of microRNAs (miRNAs) or anti-microRNAs (anti-miRNAs) that can induce angiogenesis to aid in blood vessel formation for vascular tissue engineering in ischemic diseases such as peripheral arterial disease (PAD) and stroke, cardiac diseases and skin and bone tissue engineering are discussed. Endothelial cells form the endothelium of the blood vessel and are recognized as the primary cell type that drives angiogenesis and studied in the applications that were reviewed. Besides endothelial cells, mesenchymal stem cells (MSCs) can also play a pivotal role in these applications, specifically, by secreting growth factors or cytokines for paracrine signaling and/or as constituent cells in the new blood vessel formed. In addition to delivering miRNAs or cells transfected/transduced with miRNAs for angiogenesis and vascular tissue engineering, the utilization of extracellular vesicles (EVs), such as exosomes, microvesicles and EVs collectively, have been more recently explored. Pro-angiogenic miRNAs and anti-miRNAs contribute to angiogenesis by targeting the 3’-UTR of targets to upregulate pro-angiogenic factors such as vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and hypoxia-inducible factor-1 (HIF-1), increase the transduction of VEGF signaling through the PI3K/AKT and Ras/Raf/MEK/ERK signaling pathways such as phosphatase and tensin homolog (PTEN) or regulating the signaling of other pathways important for angiogenesis such as the Notch signaling pathway and the pathway to produce nitric oxide. In conclusion, angiogenic-inducing miRNAs and anti-miRNAs are promising tools for vascular tissue engineering for several applications; however, future work should emphasize optimizing the delivery and usage of these therapies as miRNAs can also be associated with the negative implications of cancer.

Hepatocellular carcinoma (HCC) is the fifth most common type of cancer diagnosed and the second leading cause of death worldwide. Despite advancement in current treatments for HCC, the prognosis for this cancer is still unfavorable. This comprehensive review article focuses on all the current technology that applies biomaterials to treat and study liver cancer, thus showing the versatility of biomaterials to be used as smart tools in this complex pathologic scenario. Specifically, after introducing the liver anatomy and pathology by focusing on the available treatments for HCC, this review summarizes the current biomaterial-based approaches for systemic delivery and implantable tools for locally administrating bioactive factors and provides a comprehensive discussion of the specific therapies and targeting agents to efficiently deliver those factors. This review also highlights the novel application of biomaterials to study HCC, which includes hydrogels and scaffolds to tissue engineer 3D in vitro models representative of the tumor environment. Such models will serve to better understand the tumor biology and investigate new therapies for HCC. Special focus is given to innovative approaches, e.g., combined delivery therapies, and to alternative approaches—e.g., cell capture—as promising future trends in the application of biomaterials to treat HCC.

Background: Combination antiretroviral therapy has significantly advanced HIV-1 infection treatment. However, HIV-1 remains persistent in the brain; the inaccessibility of the blood–brain barrier a...