Cenderitide-eluting film for potential cardiac patch applications

Abstract

Cenderitide, also known as CD-NP, is a designer peptide developed by combining native mammalian c-type natriuretic peptide (CNP) and the C-terminus isolated from the dendroapis natriuretic peptide (DNP) of the venom from the green mamba. In early studies, intravenous and subcutaneous infusion of cenderitide was reported to reduce left ventricular (LV) mass and ameliorate cardiac remodelling. In this work, biodegradable polymeric films encapsulating CD-NP were developed and were investigated for their in vitro release and degradation characteristics. Subsequently, the bioactivity of released peptide and its effects on human cardiac fibroblast (HCF) were explored. We achieved sustained release from three films with low, intermediate and high release profiles for 30 days. Moreover, the bioactivity of released peptide was verified from the elevated production of cyclic guanosine monophospate (cGMP). The CD-NP released from films was able to inhibit the proliferation of hypertrophic HCF as well as suppress DNA synthesis in HCF. Furthermore, the sustained delivery from films showed comparable or superior suppressive actions on hypertrophic HCF compared to daily infusion of CD-NP. The results suggest that these films could be used to inhibit fibrosis and reduce cardiac remodelling via local delivery as cardiac patches.

Figure 1. Accumulated release profiles of CD-NP loaded films for 30 days.

(a) Accumulated peptide release profiles of film 1, 2 and 3 and (b) bottom left graph shows the release concentrations of film 1, 2 and 3 over 30 days; top right graph is a zoomed in on the bottom left graph.

Figure 2. Molecular mass and mass loss of CD-NP loaded films.

(a) Molecular mass change and (b) mass loss of CD-NP loaded film 1, 2 and 3 over 30 days.

Figure 3. Surface morphology of films loaded with CD-NP.

SEM micrograph on day 0 of CD-NP loaded (a) film 1, (b) film 2 and (c) film 3 and after day 30 release in (d) film 1, (e) film 2 and (f) film 3.

Figure 4. Cyclic 3′5′ guanosine monophosphate (cGMP) generation in human cardiac fibroblast (HCF).

cGMP generation in HCF induced by (a) different CD-NP concentration and (b) 24 hour peptide released from film 1, 2 and 3, *p<0.05 versus control.

Figure 5. Cell Index (CI) measurements.

Cell Index (CI) measurement of control compared to (a) Daily infusion of CD-NP, (b) film 1, (c) film 2 and (d) film 3 from the RTCA xCELLigence.

Figure 6. Correlation between relative cell index (RCI) and CD-NP concentration.

Correlation between RCI (primary y-axis) and peptide concentration (secondary y-axis) of (a) Daily infusion of CD-NP, (b) film 1, (c) film 2 and (d) film 3 over 5 days (x-axis).

Figure 7. Effects of CD-NP on human cardiac fibroblast (HCF).

Relative anti-proliferation actions of (a) CD-NP of different concentration and (b) CD-NP released from film 1, 2 and 3 (1 day, 2 days, 3 days and 5 days) in HCF via colormetric bromodeoxyuridine (BrdU), *p<0.05.