Secreted Matrix Metalloproteinase-9 of Proliferating Smooth Muscle Cells as a Trigger for Drug Release from Stent Surface Polymers in Coronary Arteries

Biopolymeric Coatings for Local Release of Therapeutics from Biomedical Implants

The deployment of structures that enable localized release of bioactive molecules can result in more efficacious treatment of disease and better integration of implantable bionic devices. The strategic design of a biopolymeric coating can be used to engineer the optimal release profile depending on the task at hand. As illustrative examples, here advances in delivery of drugs from bone, brain, ocular, and cardiovascular implants are reviewed. These areas are focused to highlight that both hard and soft tissue implants can benefit from controlled localized delivery. The composition of biopolymers used to achieve appropriate delivery to the selected tissue types, and their corresponding outcomes are brought to the fore. To conclude, key factors in designing drug-loaded biopolymeric coatings for biomedical implants are highlighted.

Endothelial Foxp1 Regulates Neointimal Hyperplasia Via Matrix Metalloproteinase-9/Cyclin Dependent Kinase Inhibitor 1B Signal Pathway

Background The endothelium is essential for maintaining vascular physiological homeostasis and the endothelial injury leads to the neointimal hyperplasia because of the excessive proliferation of vascular smooth muscle cells. Endothelial Foxp1 (forkhead box P1) has been shown to control endothelial cell (EC) proliferation and migration in vitro. However, whether EC-Foxp1 participates in neointimal formation in vivo is not clear. Our study aimed to investigate the roles and mechanisms of EC-Foxp1 in neointimal hyperplasia. Methods and Results The wire injury femoral artery neointimal hyperplasia model was performed in Foxp1 EC-specific loss-of-function and gain-of-function mice. EC-Foxp1 deletion mice displayed the increased neointimal formation through elevation of vascular smooth muscle cell proliferation and migration, and the reduction of EC proliferation hence reendothelialization after injury. In contrast, EC-Foxp1 overexpression inhibited the neointimal formation. EC-Foxp1 paracrine regulated vascular smooth muscle cell proliferation and migration via targeting matrix metalloproteinase-9. Also, EC-Foxp1 deletion impaired EC repair through reduction of EC proliferation via increasing cyclin dependent kinase inhibitor 1B expression. Delivery of cyclin dependent kinase inhibitor 1B-siRNA to ECs using RGD (Arg-Gly-Asp)-peptide magnetic nanoparticle normalized the EC-Foxp1 deletion-mediated impaired EC repair and attenuated the neointimal formation. EC-Foxp1 regulates matrix metalloproteinase-9/cyclin dependent kinase inhibitor 1B signaling pathway to control injury induced neointimal formation. Conclusions Our study reveals that targeting EC-Foxp1-matrix metalloproteinase-9/cyclin dependent kinase inhibitor 1B pathway might provide future novel therapeutic interventions for restenosis.

Spun Biotextiles in Tissue Engineering and Biomolecules Delivery Systems

Nowadays, tissue engineering is described as an interdisciplinary field that combines engineering principles and life sciences to generate implantable devices to repair, restore and/or improve functions of injured tissues. Such devices are designed to induce the interaction and integration of tissue and cells within the implantable matrices and are manufactured to meet the appropriate physical, mechanical and physiological local demands. Biodegradable constructs based on polymeric fibers are desirable for tissue engineering due to their large surface area, interconnectivity, open pore structure, and controlled mechanical strength. Additionally, biodegradable constructs are also very sought-out for biomolecule delivery systems with a target-directed action. In the present review, we explore the properties of some of the most common biodegradable polymers used in tissue engineering applications and biomolecule delivery systems and highlight their most important uses.

Design, Synthesis, and Characterization of a Paclitaxel Formulation Activated by Extracellular MMP9

The concept of triggered drug release offers a possibility to overcome the toxic side effects of chemotherapeutics in cancer treatment by reducing systemic exposure to the active drug. In the present work, the concept foresees the use of the extracellular enzyme MMP9 as an enzymatic trigger for drug release in the proximity of tumor cells.

METHODS

A paclitaxel-hemisuccinate-peptide conjugate as a building block for self-assembling nanoparticles was synthesized using standard conjugation approaches. The building block was purified via preparative HPLC and analyzed by LC-MS. Nanoparticles were formed using the nanoprecipitation method and characterized. For selection of a suitable in vitro model system, common bioanalytical methods were used to determine mRNA expression, enzyme amount, and activity of MMP9.

RESULTS

The MMP9-labile prodrug was synthesized and characterized. Nanoparticles were formed out of MMP9-labile conjugate-building blocks. The nanoparticle's diameter averaged at around 120 nm and presented a spherical shape. LN-18 cells, a glioblastoma multiforme derived cell line, were chosen as an in vitro model based on findings in cancer tissue and cell line characterization. The prodrug showed cytotoxicity in LN-18 cells, which was reduced by addition of an MMP9 inhibitor.

CONCLUSION

taken together, we confirmed increased MMP9 in several cancer tissues (cervical, esophageal, lung, and brain) compared to healthy tissue and showed the effectiveness of MMP9-labile prodrug in in vitro tests.

Ginkgetin ameliorates experimental atherosclerosis in rats

Atherosclerosis is a common disease seriously detrimental to human health. Natural products are important sources of therapeutic candidates for atherosclerosis. We here evaluated the effects of ginkgetin on experimental atherosclerosis in rats and explored the underlying mechanisms. Atherosclerosis was induced by high-fat diet for 12 weeks combined with single intraperitoneal injection of vitamin D3 in rats. The atherosclerotic rats were then treated with ginkgetin at 25, 50 and 100 mg/kg/d or simvastatin at 2 mg/kg/d for 8 weeks. Blood and thoracic aortas were collected for analyses of histopathology, lipid deposition, serum biochemistry, matrix metalloproteinases (MMPs), and nitric oxide (NO)/NO synthase (NOS) system. We found that ginkgetin improved thoracic aortic intima structure, reduced intima-media thickness and intima/media ratio, and attenuated lipid deposition in aorta of atherosclerotic rats. Ginkgetin also decreased the serum levels of total cholesterol, triglyceride and low-density lipoprotein cholesterol, but restored the serum levels of high-density lipoprotein cholesterol in atherosclerotic rats. Additionally, ginkgetin reduced the mRNA and protein expression of MMP-2 and MMP-9 in thoracic aortas of rats with atherosclerosis. Further examinations showed that ginkgetin increased the NO and NOS levels in serum and thoracic aortas. Ginkgetin also unregulated the expression of endothelial NOS and downregulated the expression of inducible NOS at both mRNA and protein levels in thoracic aortas of atherosclerotic rats. Altogether, ginkgetin showed therapeutic effects on experimental atherosclerosis associated with improving lipid profile and modulating the MMPs and NO/NOS systems in rats. Ginkgetin could be a promising candidate for the treatment of atherosclerosis.

Evidence for the Involvement of Matrix-Degrading Metalloproteinases (MMPs) in Atherosclerosis

Atherosclerosis leads to blockage of arteries, culminating in myocardial infarction, and stroke. The involvement of matrix-degrading metalloproteinases (MMPs) in atherosclerosis is established and many studies have highlighted the importance of various MMPs in this process. MMPs were first implicated in atherosclerosis due to their ability to degrade extracellular matrix components, which can lead to increased plaque instability. However, more recent work has highlighted a multitude of roles for MMPs in addition to breakdown of extracellular matrix proteins. MMPs are now known to be involved in various stages of plaque progression: from initial macrophage infiltration to plaque rupture. This chapter summarizes the development and progression of atherosclerotic plaques and the contribution of MMPs. We provide data from human studies showing the effect of MMP polymorphisms and the expression of MMPs in both the atherosclerotic plaque and within plasma. We also discuss work in animal models of atherosclerosis that show the effect of gain or loss of function of MMPs. Together, the data provided from these studies illustrate that MMPs are ideal targets as both biomarkers and potential drug therapies for atherosclerosis.