Heart failure has a five-year mortality rate approaching 50%. Inducing angiogenesis following a myocardial infarction is hypothesized to reduce cardiomyocyte death and tissue damage, thereby preventing heart failure. Herein, a novel nano-in-gel delivery system for vascular endothelial growth factor (VEGF), composed of star-shaped polyglutamic acid-VEGF nanoparticles in a tyramine-modified hyaluronic acid hydrogel (nano-VEGF-HA-TA), is investigated. The ability of the nano-VEGF-HA-TA system to induce angiogenesis is assessed in vivo using a chick chorioallantoic membrane model (CAM). The formulation is then integrated with a custom-made, clinically relevant catheter suitable for minimally invasive endocardial delivery and the effect of injection on hydrogel properties is examined. Nano-VEGF-HA-TA is biocompatible on a CAM assay and significantly improves blood vessel branching (p < 0.05) and number (p < 0.05) compared to a HA-TA hydrogel without VEGF. Nano-VEGF-HA-TA is successfully injected through a 1.2 m catheter, without blocking or breaking the catheter and releases VEGF for 42 days following injection in vitro. The released VEGF retains its bioactivity, significantly improving total tubule length on a Matrigel® assay and human umbilical vein endothelial cell migration on a Transwell® migration assay. This VEGF-nano in a HA-TA hydrogel delivery system is successfully integrated with an appropriate device for clinical use, demonstrates promising angiogenic properties in vivo and is suitable for further clinical translation.
Stromal-Derived Factor 1α (SDF) is an angiogenic, chemotactic protein with significant potential for applications in a range of clinical areas, including wound healing, myocardial infarction and orthopaedic regenerative approaches. The 26-min in vivo half-life of SDF, however, has limited its clinical translation to date. In this study, we investigate the use of star-shaped or linear poly(glutamic acid) (PGA) polypeptides to produce PGA-SDF nanoparticles, which can be incorporated into a tyramine-modified hyaluronic acid hydrogel (HA-TA) to facilitate sustained localised delivery of SDF. The physicochemical properties and biocompatibility of the PGA-SDF nanoparticle formulations were extensively characterised prior to incorporation into a HA-TA hydrogel. The biological activity of the SDF released from the nano-in-gel system was determined on Matrigel®, scratch and Transwell® migration assays. Both star-shaped and linear PGA facilitated SDF nanoparticle formation with particle sizes from 255-305 nm and almost complete SDF complexation. Star-PGA-SDF demonstrated superior biocompatibility and was incorporated into a HA-TA gel, which facilitated sustained SDF release for up to 35 days in vitro. Released SDF significantly improved gap closure on a scratch assay, produced a 2.8-fold increase in HUVEC Transwell® migration and a 1.5-fold increase in total tubule length on a Matrigel® assay at 12 h compared to untreated cells. Overall, we present a novel platform system for the sustained delivery of bioactive SDF from a nano-in-gel system which could be adapted for a range of biomedical applications.
- Klíčová slova
- angiogenesis, chemotaxis, hydrogel, nanoparticle, protein delivery, stromal-derived factor, sustained release,
- Publikační typ
- časopisecké články MeSH
The incorporation of the RGD peptide (arginine-glycine-aspartate) into biomaterials has been proposed to promote cell adhesion to the matrix, which can influence and control cell behaviour and function. While many studies have utilised RGD modified biomaterials for cell delivery, few have examined its effect under the condition of reduced oxygen and nutrients, as found at ischaemic injury sites. Here, we systematically examine the effect of RGD on hMSCs in hyaluronic acid (HA) hydrogel under standard and ischaemic culture conditions, to elucidate under what conditions RGD has beneficial effects over unmodified HA and its effectiveness in improving cell viability. Results demonstrate that under standard culture conditions, RGD significantly increased hMSC spreading and the release of vascular endothelial factor-1 (VEGF) and monocyte chemoattractant factor-1 (MCP-1), compared to unmodified HA hydrogel. As adhesion is known to influence cell survival, we hypothesised that cells in RGD hydrogels would exhibit increased cell viability under ischaemic culture conditions. However, results demonstrate that cell viability and protein release was comparable in both RGD modified and unmodified HA hydrogels. Confocal imaging revealed cellular morphology indicative of weak cell adhesion. Subsequent investigations found that RGD was could exert positive effects on encapsulated cells under ischaemic conditions but only if hMSCs were pre-cultured under standard conditions to allow strong adhesion to RGD before exposure. Together, these results provide novel insight into the value of RGD introduction and suggest that the adhesion of hMSCs to RGD prior to delivery could improve survival and function at ischaemic injury sites. STATEMENT OF SIGNIFICANCE: The development of a biomaterial scaffold capable of maintaining cell viability while promoting cell function is a major research goal in the field of cardiac tissue engineering. This study confirms the suitability of a modified HA hydrogel whereby stem cells in the modified hydrogel showed significantly greater cell spreading and protein secretion compared to cells in the unmodified HA hydrogel. A pre-culture period allowing strong adhesion of the cells to the modified hydrogel was shown to improve cell survival under conditions that mimic the myocardium post-MI. This finding may have a significant impact on the use and timelines of modifications to improve stem cell survival in harsh environments like the injured heart.
- Klíčová slova
- Hyaluronic acid, Hydrogel, Mesenchymal stem cell, Myocardial infarction, RGD, Stem cell delivery,
- MeSH
- buněčná adheze účinky léků MeSH
- buněčné kultury MeSH
- hydrogely chemie MeSH
- hypoxie buňky fyziologie MeSH
- kyselina hyaluronová chemie MeSH
- lidé MeSH
- mezenchymální kmenové buňky cytologie fyziologie MeSH
- oligopeptidy chemie MeSH
- tkáňové inženýrství metody MeSH
- tkáňové podpůrné struktury chemie MeSH
- viabilita buněk účinky léků MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- arginyl-glycyl-aspartic acid MeSH Prohlížeč
- hydrogely MeSH
- kyselina hyaluronová MeSH
- oligopeptidy MeSH
The 5-year mortality rate for heart failure borders on 50%. The main cause is an ischaemic cardiac event where blood supply to the tissue is lost and cell death occurs. Over time, this damage spreads and the heart is no longer able to pump efficiently. Increasing vascularisation of the affected area has been shown to reduce patient symptoms. The growth factors required to do this have short half-lives making development of an efficacious therapy difficult. Herein, the angiogenic growth factor Vascular Endothelial Growth Factor (VEGF) is complexed electrostatically with star-shaped or linear polyglutamic acid (PGA) polypeptides. Optimised PGA-VEGF nanomedicines provide VEGF encapsulation of > 99% and facilitate sustained release of VEGF for up to 28 days in vitro. The star-PGA-VEGF nanomedicines are loaded into a percutaneous delivery compliant hyaluronic acid hydrogel. Sustained release of VEGF from the composite nano-in-gel system is evident for up to 35 days and the released VEGF has comparable bioactivity to free, fresh VEGF when tested on both Matrigel® and scratch assays. The final star-PGA-VEGF nanomedicine-loaded hydrogel is biocompatible and provides sustained release of bioactive VEGF. Therefore, we report the development of novel, self-assembling PGA-VEGF nanomedicines and their incorporation into a hyaluronic acid hydrogel that is compatible with medical devices to enable minimally invasive delivery to the heart. The final star-PGA-VEGF nanomedicine-loaded hydrogel is biocompatible and provides sustained release of bioactive VEGF. This formulation provides the basis for optimal spatiotemporal delivery of an angiogenic growth factor to the ischaemic myocardium.
- Klíčová slova
- Angiogenesis, Growth factor, Ischaemia, Nanoparticle, Star polypeptide,
- MeSH
- aplikace kožní MeSH
- endoteliální buňky pupečníkové žíly (lidské) MeSH
- hydrogely MeSH
- ischemická choroba srdeční farmakoterapie MeSH
- kyselina polyglutamová chemie MeSH
- léky s prodlouženým účinkem MeSH
- lidé MeSH
- nanočástice MeSH
- statická elektřina MeSH
- vaskulární endoteliální růstový faktor A chemie farmakologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- hydrogely MeSH
- kyselina polyglutamová MeSH
- léky s prodlouženým účinkem MeSH
- vaskulární endoteliální růstový faktor A MeSH
The limited regenerative capacity of the heart after a myocardial infarct results in remodeling processes that can progress to congestive heart failure (CHF). Several strategies including mechanical stabilization of the weakened myocardium and regenerative approaches (specifically stem cell technologies) have evolved which aim to prevent CHF. However, their final performance remains limited motivating the need for an advanced strategy with enhanced efficacy and reduced deleterious effects. An epicardial carrier device enabling a targeted application of a biomaterial-based therapy to the infarcted ventricle wall could potentially overcome the therapy and application related issues. Such a device could play a synergistic role in heart regeneration, including the provision of mechanical support to the remodeling heart wall, as well as providing a suitable environment for in situ stem cell delivery potentially promoting heart regeneration. In this study, we have developed a novel, single-stage concept to support the weakened myocardial region post-MI by applying an elastic, biodegradable patch (SPREADS) via a minimal-invasive, closed chest intervention to the epicardial heart surface. We show a significant increase in %LVEF 14 days post-treatment when GS (clinical gold standard treatment) was compared to GS + SPREADS + Gel with and without cells (p ≤ 0.001). Furthermore, we did not find a significant difference in infarct quality or blood vessel density between any of the groups which suggests that neither infarct quality nor vascularization is the mechanism of action of SPREADS. The SPREADS device could potentially be used to deliver a range of new or previously developed biomaterial hydrogels, a remarkable potential to overcome the translational hurdles associated with hydrogel delivery to the heart.
- Klíčová slova
- Epicardial carrier device, Extravascular device, Hyaluronic acid hydrogel, Myocardial infarction, Stem cell delivery, Ventricular stabilization,
- MeSH
- biokompatibilní materiály MeSH
- buněčná a tkáňová terapie přístrojové vybavení metody MeSH
- design vybavení MeSH
- hydrogely aplikace a dávkování chemie farmakologie MeSH
- infarkt myokardu patofyziologie terapie MeSH
- kyselina hyaluronová MeSH
- lidé MeSH
- mezenchymální kmenové buňky * účinky léků MeSH
- perikard MeSH
- pohyb buněk účinky léků MeSH
- prasata MeSH
- transplantace mezenchymálních kmenových buněk MeSH
- tuková tkáň cytologie MeSH
- viskozita MeSH
- vstřebatelné implantáty * MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- biokompatibilní materiály MeSH
- hydrogely MeSH
- kyselina hyaluronová MeSH
The effect of hydrazide linkers on the formation and mechanical properties of hyaluronan hydrogels was intensively evaluated. The reaction kinetics of hydrazone formation was monitored by NMR spectroscopy under physiological conditions where polyaldehyde hyaluronan (unsaturated: ΔHA-CHO, saturated: HA-CHO) was reacted with various hydrazides to form hydrogels. Linear (adipic, oxalic dihydrazide) and branched (N,N´,N´´-tris(hexanoylhydrazide-6-yl)phosphoric triamide and 4-arm-PEG hydrazide) hydrazides were compared as crosslinking agents. The mechanical properties of hydrogels were also modified by attaching a hydrophobic chain to HA-CHO; however, it was found that this modification did not lead to an increase in hydrogel stiffness. Cytotoxicity tests showed that all tested hydrazide crosslinkers reduced the viability of cells only slightly, and that the final hyaluronan hydrogels were non-toxic materials.
- Klíčová slova
- Schiff base, acylation, hyaluronan, hydrazone, hydrogel,
- MeSH
- acylace MeSH
- biokompatibilní materiály chemická syntéza chemie toxicita MeSH
- buňky Swiss 3T3 MeSH
- hydraziny chemická syntéza chemie toxicita MeSH
- hydrazony chemická syntéza chemie toxicita MeSH
- hydrogely chemická syntéza chemie toxicita MeSH
- kinetika MeSH
- koncentrace vodíkových iontů MeSH
- kyselina hyaluronová analogy a deriváty chemická syntéza toxicita MeSH
- modul pružnosti MeSH
- myši MeSH
- reagencia zkříženě vázaná chemická syntéza chemie toxicita MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- biokompatibilní materiály MeSH
- hydraziny MeSH
- hydrazony MeSH
- hydrogely MeSH
- kyselina hyaluronová MeSH
- reagencia zkříženě vázaná MeSH
The adverse immune responses to implantable biomedical devices is a general problem with important consequences for the functionality of implants. Immunomodulatory soft hydrogel-based interfaces between the implant and the host can attenuate these reactions. Moreover, encapsulation of the patient's own immune cells into these interfaces can lead to the personalisation of implants from the immune reaction point of view. Herein, we described a co-crosslinkable composite hydrogel (composed of gelatin and hyaluronic acid), which could be used for the encapsulation of macrophages in the presence of an anti-inflammatory phenotype-fixing cytokine cocktail. To mimick the incoming immune cells on the coating surface in vivo, peripheral blood mononuclear cells were seeded on the hydrogels. The encapsulation of monocytic cells into the composite hydrogels in the presence of cytokine cocktails at 5× or 10× concentrations led to the spreading of the encapsulated cells instead of the formation of clusters. Moreover, the secretion of the anti-inflammatory cytokines IL-1RA and CCL-18 was significantly increased. The attachment of PBMC to the surface of the hydrogel is dependent on the hydrogel composition and also significantly increased in the presence of the cytokine cocktail together with the number of CD68+ cells on the hydrogel surface. Our study demonstrates that the delivery of a polarisation cocktail with biocompatible hydrogels can control the initial response by the incoming immune cells. This effect can be improved by the encapsulation of autologous monocytes that are also polarised by the cytokine cocktail and secrete additional anti-inflammatory cytokines. This interface can fine tune the initial immune response to an implanted biomaterial in a personalised manner.
- Publikační typ
- časopisecké články MeSH
Injectable hydrogels that aim to mechanically stabilise the weakened left ventricle wall to restore cardiac function or to deliver stem cells in cardiac regenerative therapy have shown promising data. However, the clinical translation of hydrogel-based therapies has been limited due to difficulties injecting them through catheters. We have engineered a novel catheter, Advanced Materials Catheter (AMCath), that overcomes translational hurdles associated with delivering fast-gelling covalently cross-linked hyaluronic acid hydrogels to the myocardium. We developed an experimental technique to measure the force required to inject such hydrogels and determined the mechanical/viscoelastic properties of the resulting hydrogels. The preliminary in vivo feasibility of delivering fast-gelling hydrogels through AMCath was demonstrated by accessing the porcine left ventricle and showing that the hydrogel was retained in the myocardium post-injection (three 200 μL injections delivered, 192, 204 and 183 μL measured). However, the mechanical properties of the hydrogels were reduced by passage through AMCath (≤20.62% reduction). We have also shown AMCath can be used to deliver cardiopoietic adipose-derived stem cell-loaded hydrogels without compromising the viability (80% viability) of the cells in vitro. Therefore, we show that hydrogel/catheter compatibility issues can be overcome as we have demonstrated the minimally invasive delivery of a fast-gelling covalently cross-linked hydrogel to the beating myocardium.
- Klíčová slova
- Hydrogel, catheter, hyaluronic acid, minimally invasive delivery, myocardial infarction,
- MeSH
- biokompatibilní materiály aplikace a dávkování MeSH
- buněčné linie MeSH
- design vybavení MeSH
- hydrogely aplikace a dávkování MeSH
- imobilizované buňky cytologie transplantace MeSH
- infarkt myokardu terapie MeSH
- injekce MeSH
- kmenové buňky cytologie MeSH
- kyselina hyaluronová aplikace a dávkování MeSH
- lidé MeSH
- prasata MeSH
- reagencia zkříženě vázaná aplikace a dávkování MeSH
- srdeční katétry * MeSH
- systémy cílené aplikace léků přístrojové vybavení MeSH
- transplantace kmenových buněk MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- biokompatibilní materiály MeSH
- hydrogely MeSH
- kyselina hyaluronová MeSH
- reagencia zkříženě vázaná MeSH
