Understanding greater cardiomyocyte functions on aligned compared to random carbon nanofibers in PLGA
Authors: Sher Bahadar Khan
Hadi M Marwani
Abdullah M Asiri
Thomas J Webster
Journal: International Journal of Nanomedicine (2014)
Discipline: PHARMACOLOGY & TOXICOLOGY
Keywords: aligned; anisotropy; carbon nanofibers; cardiomyocytes; fibronectin

Abstract:  Previous studies have demonstrated greater cardiomyocyte density on carbon nanofibers (CNFs) aligned (compared to randomly oriented) in poly(lactic-co-glycolic acid) (PLGA) composites. Although such studies demonstrated a closer mimicking of anisotropic electrical and mechanical properties for such aligned (compared to randomly oriented) CNFs in PLGA composites, the objective of the present in vitro study was to elucidate a deeper mechanistic understanding of how cardiomyocyte densities recognize such materials to respond more favorably. Results showed lower wettability (greater hydrophobicity) of CNFs embedded in PLGA compared to pure PLGA, thus providing evidence of selectively lower wettability in aligned CNF regions. Furthermore, the results correlated these changes in hydrophobicity with increased adsorption of fibronectin, laminin, and vitronectin (all proteins known to increase cardiomyocyte adhesion and functions) on CNFs in PLGA compared to pure PLGA, thus providing evidence of selective initial protein adsorption cues on such CNF regions to promote cardiomyocyte adhesion and growth. Lastly, results of the present in vitro study further confirmed increased cardiomyocyte functions by demonstrating greater expression of important cardiomyocyte biomarkers (such as Troponin-T, Connexin-43, and Œ±-sarcomeric actin) when CNFs were aligned compared to randomly oriented in PLGA. In summary, this study provided evidence that cardiomyocyte functions are improved on CNFs aligned in PLGA compared to randomly oriented in PLGA since CNFs are more hydrophobic than PLGA and attract the adsorption of key proteins (fibronectin, laminin, and vironectin) that are known to promote cardiomyocyte adhesion and expression of important cardiomyocyte functions. Thus, future studies should use this knowledge to further design improved CNF:PLGA composites for numerous cardiovascular applications. 

Retracted: No

PubPeer comments:
 Figure 1 of this paper looks very similar to Figure 1 of a slightly older paper by the same authors, i.e. Abdullah M Asiri et al., International Journal of Nanomedicine 2014:9 5533u20135539, DOI: 10.2147 IJN.S71587 . The older paper is listed as reference 12 in the citations, but the figure itself does not specifically mentions in the legend that it is a reprint from an older paper. Could the authors please clarify?  , 
 We are looking into this. It does appear to be the same image and if not properly cited, we will correct. , 
 May 19, 2021 The authors have advised the note section for Figure 1 on page 90 is incorrect. The correct Notes section is as follows: Notes: SEM images showing the distribution of CNF in the PLGA matrix at 50:50 wt% at (A) random orientation and (B) aligned orientation to mimic the natural anisotropy of cardiac tissue. (C) AFM line scan of the 50:50 CNF:PLGA aligned composite, demonstrating micrometer-scale alignment of the CNFs on the PLGA surface. AFM scans for the randomly oriented CNFs in PLGA matched that of the CNF patterned region. Scale bars =20 u00b5m. Reproduced from Asiri A, Marwani H, Khan SB, Webster T. Greater cardiomyocyte density on aligned compared with random carbon nanofibers in polymer composites. Int J Nanomedicine. 2014;9(1):5533-5539.12 ,