Toward the Development of Partially Biodegradable and Injectable Thermoresponsive Hydrogels for Potential Biomedical Applications

Vascular endothelial growth factor (VEGF), an independent mitogen, has been reported to induce angiogenesis and thus attenuates the damage induced by myocardial infarction (MI). VEGF165 is the most abundant and predominant isoform of VEGF. This study investigates whether this effect could be strengthened by local intramyocardial injection of VEGF165 along with a novel biodegradable Dex-PCL-HEMA/PNIPAAm hydrogel and ascertains its possible mechanism of action. Rat models of myocardial infarction were induced by coronary artery ligation. Phosphate-buffered saline (PBS group), Dex-PCL-HEMA/PNIPAAm hydrogel (Gel group), phosphate-buffered saline containing VEGF165 (VP group), and hydrogel containing VEGF165 (VPG group) were injected into a peri-infarcted area of cardiac tissue immediately after myocardial infarction, respectively. The sham group was thoracic but without myocardial infarction. The injection of VEGF165 along with a hydrogel induced angiogenesis, reduced collagen content and MI area, inhibited cell apoptosis, increased the level of VEGF165 protein and the expression of flk-1 and flt-1, and improved cardiac function compared with the injection of either alone after MI in rats. The results suggest that injection of VEGF165 along with a hydrogel acquires more cardioprotective effects than either alone in rat with MI by sustained release of VEGF165, then may enhance the feedback between VEGF and its receptors flk-1 and flt-1.

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“…The Dex-PCL-HEMA/PNIPAAm hydrogel, a novel thermosensitive polymer, is biocompatible, biodegradable and nontoxic [37,38].…”

Section: Discussionmentioning

confidence: 99%

Intramyocardial delivery of VEGF165 via a novel biodegradable hydrogel induces angiogenesis and improves cardiac function after rat myocardial infarction

Zhu

Jiang

et al. 2015

Heart Vessels

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“…The resulting hydrogels (Dex-PCL-HEMA/PNIPAAm) can shift from sol to gel at around 33°C within 30 s and the reversible course occurs in the same time, which enables the materials to be introduced into the site-specific organ, tissue or body cavity with improved applicability and comfort via injection. Subcutaneous hydrogel injection demonstrated good biocompatibility [11]. …”

Section: Methodsmentioning

confidence: 99%

Injectable Hydrogel Helps Bone Marrow-Derived Mononuclear Cells Restore Infarcted Myocardium

Wang

Jiang

et al. 2010

Cardiology

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Backgrounds: Experimental and clinical studies have suggested that cell implantation could improve cardiac function after myocardial infarction (MI). However, this technique was limited by decreased engraftment and survival of transplanted cells within the ischemic tissue. The present study was performed to investigate whether implantation of bone marrow-derived mononuclear cells (BMMNCs) encapsulated in hydrogel could increase cell engraftment and help to restore cardiac function of MI rabbits. Methods: MI was induced in rabbits by coronary artery ligation. One week later, cell culture medium, Dex-PCL-HEMA/PNIPAAm hydrogel, BMMNCs in medium or BMMNCs in hydrogel were injected into the infarcted area of the left ventricle (LV). Results: Increased cell engraftment was observed 48 h after injection when cells were encapsulated in hydrogel; 30 days after treatment, echocardiographic studies showed that injection of BMMNCs in hydrogel preserved LV ejection fraction and attenuated LV dilatation compared with other groups. Histological analysis indicated that injection of BMMNCs in hydrogel enhanced neovascular formation and prevented scar expansion compared with the other groups. Conclusion: Injection of hydrogel-encapsulated BMMNCs increased cell engraftment and improved LV function; this technique may serve as an effective approach to restore infarcted myocardium.

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“…Similar work was done by Zhuo et al grafting PNIPAAm and PVCL-HEMA onto a dextran chain to produce injectable and biodegradable hydrogels. This gel was capable of delivering drugs over several days with negligible cytotoxicity [82].…”

Section: Collapsed Network Swollen Networkmentioning

confidence: 99%

Thermoresponsive Polymers for Biomedical Applications

2011

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Thermoresponsive polymers are a class of "smart" materials that have the ability to respond to a change in temperature; a property that makes them useful materials in a wide range of applications and consequently attracts much scientific interest. This review focuses mainly on the studies published over the last 10 years on the synthesis and use of thermoresponsive polymers for biomedical applications including drug delivery, tissue engineering and gene delivery. A summary of the main applications is given following the different studies on thermoresponsive polymers which are categorized based on their 3-dimensional structure; hydrogels, interpenetrating networks, micelles, crosslinked micelles, polymersomes, films and particles.

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Toward the Development of Partially Biodegradable and Injectable Thermoresponsive Hydrogels for Potential Biomedical Applications

Cited by 81 publications

References 48 publications

Intramyocardial delivery of VEGF165 via a novel biodegradable hydrogel induces angiogenesis and improves cardiac function after rat myocardial infarction

Intramyocardial delivery of VEGF165 via a novel biodegradable hydrogel induces angiogenesis and improves cardiac function after rat myocardial infarction

Injectable Hydrogel Helps Bone Marrow-Derived Mononuclear Cells Restore Infarcted Myocardium

Thermoresponsive Polymers for Biomedical Applications

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