The effect of a single injection of uniform-sized insulin-loaded PLGA microspheres on peri-implant bone formation

Enhancing Anticancer Efficacy of Formononetin Microspheres via Microfluidic Fabrication

Formononetin is a flavonoid compound with anti-tumor and anti-inflammatory properties. However, its low solubility limits its clinical use. We employed microfluidic technology to prepare formononetin-loaded PLGA-PEGDA microspheres (Degradable polymer PLGA, Crosslinking agent PEGDA), which can encapsulate and release drugs in a controlled manner. We optimized and characterized the microspheres, and evaluated their antitumor effects. The microspheres had uniform size, high drug loading efficiency, high encapsulation efficiency, and stable release for 35 days. They also inhibited the proliferation, migration, and apoptosis. The antitumor mechanism involved the induction of reactive oxygen species and modulation of Bcl-2 family proteins. These findings suggested that formononetin-loaded PLGA-PEGDA microspheres, created using microfluidic technology, could be a novel drug delivery system that can overcome the limitations of formononetin and enhance its antitumor activity.

Effects of alendronate combined with local radiotherapy on serum Akt/GSK3β and bone metabolism levels in patients with bone metastases from primary liver cancer

OBJECTIVE

To investigate the effects of alendronate combined with local radiotherapy on the level of serum Akt/GSK3β and bone metabolism in patients of primary liver cancer with bone metastases.

METHODS

Clinical data of 68 patients of primary liver cancer with bone metastases and treated in Shanghai General Hospital, a hospital affiliated to Shanghai Jiao Tong University School of Medicine, were retrospectively analyzed. According to the different surgical methods, the patients were divided into a control group, with 33 cases treated with local radiotherapy plus Oxycodone hydrochloride extended-release tablets, and a study group, with 35 cases treated with alendronate combined with local radiotherapy. The remission rate and adverse reaction rate were compared between the two groups. In addition, we observed and compared the liver function indexes (total bilirubin (TBIL), alanine aminotransferase (ALT) and alkaline phosphatase (ALP)), serum Akt/GSK3β level, bone metabolism levels (bone alkaline phosphatase (BAP) and levels of osteocalcin (OST)), α-fetoprotein (AFP), vascular endothelial growth factor (VEGF), osteopontin (OPN), matrix metallopeptidase 9 (MMP-9), and quality of life of the patients in two groups before and after treatment.

RESULTS

A higher remission rate was observed in the study group (94.29%) than that in the control group (75.76%) (P<0.05). There was no significant difference in the adverse reaction rate between the study group (20.00%) and the control group (12.12%) (P>0.05). In both groups, the post-treatment serum levels of TBIL, ALT, ALP, Akt, GSK3β, AFP, VEGF, OPN, MMP-9, hardship and nausea due to cancer were all decreased, while serum levels of BAP and OST, and psychological, physical and social functions were all increased (all P<0.05). The improvement of the above indicators in the study group were better than those in the control group (all P<0.05).

CONCLUSION

The use of alendronate combined with local radiotherapy received good response in patients of primary liver cancer with bone metastasis. In addition, their liver function, bone metabolism levels and quality of life all improved without increasing adverse reactions. The underlying mechanism may be related to the regulation of Akt and GSK3β levels.

Recent advances in PLGA-based biomaterials for bone tissue regeneration

Bone regeneration is an interdisciplinary complex lesson, including but not limited to materials science, biomechanics, immunology, and biology. Having witnessed impressive progress in the past decades in the development of bone substitutes; however, it must be said that the most suitable biomaterial for bone regeneration remains an area of intense debate. Since its discovery, poly (lactic-co-glycolic acid) (PLGA) has been widely used in bone tissue engineering due to its good biocompatibility and adjustable biodegradability. This review systematically covers the past and the most recent advances in developing PLGA-based bone regeneration materials. Taking the different application forms of PLGA-based materials as the starting point, we describe each form's specific application and its corresponding advantages and disadvantages with many examples. We focus on the progress of electrospun nanofibrous scaffolds, three-dimensional (3D) printed scaffolds, microspheres/nanoparticles, hydrogels, multiphasic scaffolds, and stents prepared by other traditional and emerging methods. Finally, we briefly discuss the current limitations and future directions of PLGA-based bone repair materials. STATEMENT OF SIGNIFICANCE: As a key synthetic biopolymer in bone tissue engineering application, the progress of PLGA-based bone substitute is impressive. In this review, we summarized the past and the most recent advances in the development of PLGA-based bone regeneration materials. According to the typical application forms and corresponding crafts of PLGA-based substitutes, we described the development of electrospinning nanofibrous scaffolds, 3D printed scaffolds, microspheres/nanoparticles, hydrogels, multiphasic scaffolds and scaffolds fabricated by other manufacturing process. Finally, we briefly discussed the current limitations and proposed the newly strategy for the design and fabrication of PLGA-based bone materials or devices.

Biodegradable Polymers as Drug Delivery Systems for Bone Regeneration

Regenerative medicine has been widely researched for the treatment of bone defects. In the field of bone regenerative medicine, signaling molecules and the use of scaffolds are of particular importance as drug delivery systems (DDS) or carriers for cell differentiation, and various materials have been explored for their potential use. Although calcium phosphates such as hydroxyapatite and tricalcium phosphate are clinically used as synthetic scaffold material for bone regeneration, biodegradable materials have attracted much attention in recent years for their clinical application as scaffolds due their ability to facilitate rapid localized absorption and replacement with autologous bone. In this review, we introduce the types, features, and performance characteristics of biodegradable polymer scaffolds in their role as DDS for bone regeneration therapy.