MicroRNA ‐2861 and nanofibrous scaffold synergistically promote human induced pluripotent stem cells osteogenic differentiation

Current advances in the development of microRNA-integrated tissue engineering strategies: a cornerstone of regenerative medicine

Regenerative medicine is an innovative scientific field focused on repairing, replacing, or regenerating damaged tissues and organs to restore their normal functions. A central aspect of this research arena relies on the use of tissue-engineered scaffolds, which serve as structural supports that mimic the extracellular matrix, providing an environment that orchestrates cell growth and tissue formation. Remarkably, the therapeutic efficacy of these scaffolds can be improved by harnessing the properties of other molecules or compounds that have crucial roles in healing and regeneration pathways, such as phytochemicals, enzymes, transcription factors, and non-coding RNAs (ncRNAs). In particular, microRNAs (miRNAs) are a class of tiny (20-24 nt), highly conserved ncRNAs that play a critical role in the regulation of gene expression at the post-transcriptional level. Accordingly, miRNAs are involved in a myriad of biological processes, including cell differentiation, proliferation, and apoptosis, as well as tissue regeneration, angiogenesis, and osteogenesis. On this basis, over the past years, a number of research studies have demonstrated that miRNAs can be integrated into tissue-engineered scaffolds to create advanced therapeutic platforms that precisely modulate cellular behavior and offer a controlled and targeted release of miRNAs to optimize tissue repair and regeneration. Therefore, in this current review, we discuss the most recent advances in the development of miRNA-loaded tissue-engineered scaffolds and provide an overview of the future outlooks that should be aborded in this area of study in order to lay the groundwork for the clinical translation of these tissue engineering approaches.

Electrospun Propolis-coated PLGA Scaffold Enhances the Osteoinduction of Mesenchymal Stem Cells

BACKGROUND

Major injuries that are caused by trauma and cancer can not be repaired through bone remodeling. The goal of bone regeneration by tissue engineering approaches is to fabricate bone implants in order to restore bone structure and functions. The use of stem cells and polymer scaffolds provides the conditions for tissue regeneration based on tissue engineering.

OBJECTIVE

This study aimed to fabricate a combined matrix of poly(lactide-co-glycolide) (PLGA) and propolis extract, which is a mixture of pollen and beeswax collected by bees from certain plants and has long been used in traditional herbal medicine, to promote the osteogenic differentiation of human adipose- derived mesenchymal stem cells (AD-MSCs).

METHODS

The scaffold was fabricated through electrospinning and was immersed in a propolis extract solution. Then, AD-MSCs were cultured and differentiated into the osteogenic lineage. The cell viability on the scaffold was evaluated by MTT assay. Osteogenic differentiation of the seeded stem cells was detected by evaluating calcium content, alkaline phosphatase (ALP) activity, and the expression of bonespecific genes.

RESULTS

The viability of cells was not affected by propolis-coated and uncoated fabricated scaffolds, while higher calcium content, ALP activity, and expression of RUNX-2, type I collagen, osteocalcin, and osteonectin were observed in cells differentiated on propolis-coated PLGA scaffold on days 7, 14, and 21 of differentiation compared to PLGA scaffold.

CONCLUSION

The results of this study showed that the presence of propolis in the scaffold could lead to better cell attachment and strengthen the osteoinduction process in stem cells.

The Landscape of microRNAs in Bone Tumor: A Comprehensive Review in Recent Studies

Cancer, the second greatest cause of mortality worldwide, frequently causes bone metastases in patients with advanced-stage carcinomas such as prostate, breast, and lung cancer. The existence of these metastases contributes to the occurrence of skeletal-related events (SREs), which are defined by excessive pain, pathological fractures, hypercalcemia, and spinal cord compression. These injurious incidents leave uncomfortably in each of the cancer patient's life quality. Primary bone cancers, including osteosarcoma (OS), chondrosarcoma (CS), and Ewing's sarcoma (ES), have unclear origins. MicroRNA (miRNA) expression patterns have been changed in primary bone cancers such as OS, CS, and ES, indicating a role in tumor development, invasion, metastasis, and treatment response. These miRNAs are persistent in circulation and exhibit distinct patterns in many forms of bone tumors, making them potential biomarkers for early detection and treatment of such diseases. Given their crucial regulatory functions in various biological processes and conditions, including cancer, this study aims to look at miRNAs' activities and possible contributions to bone malignancies, focusing on OS, CS, and ES. In conclusion, miRNAs are valuable tools for diagnosing, monitoring, and predicting OS, CS, and ES outcomes. Further research is required to fully comprehend the intricate involvement of miRNAs in these bone cancers and to develop effective miRNA-based treatments.

MiRNA-Nanofiber, the Next Generation of Bioactive Scaffolds for Bone Regeneration: A Review

Scaffold-based bone tissue engineering has been introduced as an alternative treatment option for bone grafting due to limitations in the allograft. Not only physical conditions but also biological conditions such as gene expression significantly impact bone regeneration. Scaffolds in composition with bioactive molecules such as miRNA mimics provide a platform to enhance migration, proliferation, and differentiation of osteoprogenitor cells for bone regeneration. Among scaffolds, fibrous structures showed significant advantages in promoting osteogenic differentiation and bone regeneration via delivering bioactive molecules over the past decade. Here, we reviewed the bone and bone fracture healing considerations for the impact of miRNAs on bone regeneration. We also examined the methods used to improve miRNA mimics uptake by cells, the fabrication of fibrous scaffolds, and the effective delivery of miRNA mimics using fibrous scaffold and their processes for bone development. Finally, we offer our view on the principal challenges of miRNA mimics delivery by nanofibers for bone tissue engineering.

MicroRNA-181a/b-1-encapsulated PEG/PLGA nanofibrous scaffold promotes osteogenesis of human mesenchymal stem cells

Bioactive nanofibres play a useful role in increasing the efficiency of tissue engineering scaffolds. MicroRNAs (miRs) alone, and in combination with tissue engineering scaffolds, can be effective in treating bone fractures and osteoporosis by regulating many post‐transcriptional cellular pathways. Herein, miR‐181a/b‐1 was incorporated in the electrospun poly (lactic‐co‐glycolic acid) (PLGA) nanofibres (PLGA‐miR). After characterization scaffolds, the osteoinductive capacity of the nanofibres was investigated when adipose‐derived mesenchymal stem cells (AT‐MSCs) were cultured on the PLGA and PLGA‐miR nanofibres. miR incorporating in the nanofibres has not any significant effect on the size and morphology of the nanofibres, but its biocompatibility was increased significantly compared to the empty nanofibres. Alkaline phosphatase (ALP) activity and calcium measures were evaluated as two important osteogenic markers, and the results revealed that the highest measures were observed in the AT‐MSCs cultured on PLGA‐miR nanofibres. Detected ALP activity and calcium measures in miR‐transduced AT‐MSCs cultured on TCPS were also significantly higher than AT‐MSCs cultured on PLGA and TCPS groups. The highest expression levels of bone‐related genes were observed in the AT‐MSCs cultured on PLGA‐miR nanofibres. This improvement in the osteogenic differentiation potential of the AT‐MSCs was also confirmed by evaluating osteopontin protein in the cells cultured on PLGA‐miR. It can be concluded that miR‐181a/b‐1 has a significant impact on the AT‐MSC osteogenic differentiation, and this impact synergistically increased when incorporated in the PLGA nanofibres.