Nanofibers may help treat heart attacks

August 10, 2012 by Lin Edwards report

(Medical Xpress) -- Cardiovascular diseases kill over 17 million people a year globally, according to the World Health Organization, and many more suffer heart attacks but recover. Even those who do recover are more prone to suffer heart failure or future heart attacks because the heart tissue is damaged. Attempts to produce effective therapies to promote repair and regeneration of heart tissues and blood vessels have so far mostly been unpromising.

Now new research by scientists in Taiwan and the US has found a promising treatment involving (VEGF), which promotes blood vessel re-growth. Previous attempts to develop a therapy based on VEGF were limited by the fact that the growth factor is rapidly washed out of the heart by the blood flow, but the new research solves this problem.

The team used a gel containing a lattice of self-assembling peptide nanofibers in combination with VEGF and found that the -like structure of the nanofibers held the VEGF in place, enabling it to be released slowly over a period of weeks.

The researchers, led by Assistant Professor Patrick C. H. Hsieh of the Institute of Biomedical Engineering, at the National Cheng Kung University, in Tainan, Taiwan, induced heart attacks in rats and then injected a combination of the nanofibers along with various doses of VEGF in the rats’ hearts.

They found that the combination improved heart health and provided an environment that promoted growth of new blood vessels, repair of damaged tissues and growth of new tissue. Dr. Hsieh, a cardiac surgeon, said the nanofibers provide an effective environment for attracting the stem cells that repair the damage and regenerate blood capillaries and even new arteries.

After 28 days the hearts of treated animals showed a much greater degree of repair and re-growth than the hearts of control animals. Arterial growth was five times greater in the treated animals, new heart muscle was being formed, and areas of weak, scarred tissue, were reduced. The controls received either VEGF alone or the alone. The same beneficial effects were demonstrated in rats and pigs, and no harmful side effects were noted in either species.

The paper was published in the journal Science Translational Medicine. In an accompanying article in the journal, Karen Christman of the University of California San Diego, said the study could lead to therapies to help human patients to recover more quickly and have improved quality of life during the recovery period. More research is needed to study the long-term effects and to determine the “optimal time window,” for administering the treatment, Dr Hsieh said.

Explore further: Protein switch controls how stem cells turn into new heart tissue

More information: Y.-D. Lin, C.-Y. Luo, Y.-N. Hu, M.-L. Yeh, Y.-C. Hsueh, M.-Y. Chang, D.-C. Tsai, J.-N. Wang, M.-J. Tang, E. I. Wei, M. L. Springer, P. C. Hsieh, Instructive Nanofiber Scaffolds with VEGF Create a Microenvironment for Arteriogenesis and Cardiac Repair. Sci. Transl. Med. 4, 146ra109 (2012).

ABSTRACT
Angiogenic therapy is a promising approach for tissue repair and regeneration. However, recent clinical trials with protein delivery or gene therapy to promote angiogenesis have failed to provide therapeutic effects. A key factor for achieving effective revascularization is the durability of the microvasculature and the formation of new arterial vessels. Accordingly, we carried out experiments to test whether intramyocardial injection of self-assembling peptide nanofibers (NFs) combined with vascular endothelial growth factor (VEGF) could create an intramyocardial microenvironment with prolonged VEGF release to improve post-infarct neovascularization in rats. Our data showed that when injected with NF, VEGF delivery was sustained within the myocardium for up to 14 days, and the side effects of systemic edema and proteinuria were significantly reduced to the same level as that of control. NF/VEGF injection significantly improved angiogenesis, arteriogenesis, and cardiac performance 28 days after myocardial infarction. NF/VEGF injection not only allowed controlled local delivery but also transformed the injected site into a favorable microenvironment that recruited endogenous myofibroblasts and helped achieve effective revascularization. The engineered vascular niche further attracted a new population of cardiomyocyte-like cells to home to the injected sites, suggesting cardiomyocyte regeneration. Follow-up studies in pigs also revealed healing benefits consistent with observations in rats. In summary, this study demonstrates a new strategy for cardiovascular repair with potential for future clinical translation.

Related Stories

Protein switch controls how stem cells turn into new heart tissue

July 13, 2011
(Medical Xpress) -- Oxford University researchers have identified a protein that can direct stem cells to become either new heart muscle or blood vessels.

Restoring blood flow

August 1, 2011
Tissue deprived of oxygen (ischemia) is a serious health condition that can lead to damaged heart tissue following a heart attack and, in the case of peripheral arterial disease in limbs, amputation, particularly in diabetic ...

Molecular pathway may help reduce damage after heart attack

December 14, 2011
(Medical Xpress) -- UH Manoa’s John A. Burns School of Medicine (JABSOM) Assistant Professor Michelle Matter and her colleagues in the Department of Cell and Molecular Biology and the Center for Cardiovascular Research ...

An economical, effective and biocompatible gene therapy strategy promotes cardiac repair

July 6, 2012
Dr Changfa Guo, Professor Chunsheng Wang and their co-investigators from Zhongshan hospital Fudan University, Shanghai, China have established a novel hyperbranched poly(amidoamine) (hPAMAM) nanoparticle based hypoxia regulated ...

Recommended for you

Deadly heart rhythm halted by noninvasive radiation therapy

December 13, 2017
Radiation therapy often is used to treat cancer patients. Now, doctors at Washington University School of Medicine in St. Louis have shown that radiation therapy—aimed directly at the heart—can be used to treat patients ...

Scientists rewrite our understanding of how arteries mend

December 13, 2017
Scientists from The University of Manchester have discovered how the severity of trauma to arterial blood vessels governs how the body repairs itself.

Ultra-thin tissue samples could help to understand and treat heart disease

December 12, 2017
A new method for preparing ultra-thin slices of heart tissue in the lab could help scientists to study how cells behave inside a beating heart.

Research reveals how diabetes in pregnancy affects baby's heart

December 12, 2017
Researchers at the Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research at UCLA have discovered how high glucose levels—whether caused by diabetes or other factors—keep heart cells from maturing ...

Young diabetics could have seven times higher risk for sudden cardiac death

December 12, 2017
Young diabetics could have seven times more risk of dying from sudden cardiac arrest than their peers who don't have diabetes, according to new research.

Blood flow–sensing protein protects against atherosclerosis in mice

December 12, 2017
UCLA scientists have found that a protein known as NOTCH1 helps ward off inflammation in the walls of blood vessels, preventing atherosclerosis—the narrowing and hardening of arteries that can cause heart attacks and strokes. ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.