Humidity‐Triggered Relaxation of Polyelectrolyte Complexes as a Robust Approach to Generate Extracellular Matrix Biomimetic Films

Abstract

Generating a biofunctional film that can mimic the extracellular matrix (ECM) in an efficient and robust technique that may have great potential for medical devices, tissue engineering, and regenerative medicines. Herein, a facile approach to generate ECM biomimetic films based on the humidity‐triggered relaxation of polyelectrolyte complex (PEC) nanoparticles is reported. The poly(l‐lysine) and hyaluronan are precomplexed and sprayed onto a substrate, which, via a trigger of vaporous water, can be transformed into an even and stable film. The spontaneous polymer chain interfusion (diffusion coefficient ≈1.01 × 10−9 cm2 s−1) under saturated humidity, allowing for the rapid reorganization (within 30 min) of film morphology and structure is demonstrated. A controllable and scalable way for the loading of diversified bioactive agents, as well as on‐demand modulation of stiffness is further presented. Moreover, the high‐throughput arrays and programmed patterns can be easily completed, suggesting huge potentials that surpass those of state‐of‐the‐art methods. Combined with high efficiency and flexible functionalization, it is believed that this approach should be beneficial for extending the practical applications of PEC films, such as medical implants, chip detectors, and so on.

Quenching the Macroporous Collapse of Polyelectrolyte Multilayer Films for Repeated Drug Loading

“…Besides reducing capillary pressure, exchanging water with ethanol also influences the interdiffusion of polyelectrolytes within (PEI/PAA) 15 films, as revealed by the fluorescence recovery after photobleaching (FRAP) experiments (Figure C). In such experiments, the recovery of fluorescence intensity in the bleached zone is generally due to the interdiffusion of unbleached fluorescent polyelectrolytes from outside of the zone. , As shown in Figure C, the fluorescence recovery of (PEI/PAA) 15 films in ethanol is considerably less noticeable than that in deionized water, indicating that the interdiffusion of polyelectrolyte chains can be effectively suppressed by solvent exchange to ethanol. Since the macroscopic strength of a polymeric material can be affected by its chain mobility, ,, we further tested the mechanical properties of (PEI/PAA) 15 films in deionized water and in ethanol (Figure D).…”

Hierarchical Capillary Coating to Biofunctionlize Drug-Eluting Stent for Improving Endothelium Regeneration

“…The NO generation of ECs was detected using a NO fluorescence probe (Beyotime, China) according to our previous work [61]. Briefly, the rapamycin-coated samples and rapamycin/VEGF-loaded samples were immersed in cell culture medium in 24-well plates for 24 h; the extraction culture medium of different samples was collected.…”

Mir-22-incorporated polyelectrolyte coating prevents intima hyperplasia after balloon-induced vascular injury

“…Polyelectrolyte complexes (PECs), consisting of negatively and positively charged polyelectrolytes, can form coatings in nano- or micro-scales on various surfaces through either layer-by-layer (LBL) self-assembly 18 or directly from the re-organization of PEC nanoparticles. 19 Such coatings mimic the natural assembly of the extracellular matrix (ECM) and thus are quite useful for the construction of biomimetic coatings on surfaces of different medical devices to optimize tissue responses after device in vivo implantation. 20 In addition, the PEC coatings can incorporate various kinds of growth factors, peptides, plasmids and RNAs through electrostatic interactions to preserve their bioactivities to the maximum.…”

“…For example, vascular endothelial growth factor (VEGF)-loaded poly( l -lysine)/hyaluronan (PLL/HA) polyelectrolyte coatings on stents dramatically enhance endothelial cell adhesion and proliferation. 19 PEC coatings consisting of hyaluronan (HA) and chitosan (CH) on the surfaces of the stent material NiTi alloys show anti-thrombosis and anti-fouling properties. 23 However, rare data are available now regarding whether PEC coatings can be used to load water-soluble miRs for site-specific delivery through balloons.…”