Lyotropic Liquid Crystals: A Biocompatible and Safe Material for Local Cardiac Application

Abstract

The regeneration of cardiac tissue is a multidisciplinary research field aiming to improve the health condition of the post-heart attack patient. Indeed, myocardial tissue has a poor ability to self-regenerate after severe damage. The scientific efforts focused on the research of a biomaterial able to adapt to heart tissue, thus guaranteeing the in situ release of active substances or growth promoters. Many types of hydrogels were proposed for this purpose, showing several limitations. The aim of this study was to suggest a new usage for glyceryl monooleate-based lyotropic liquid crystals (LLCs) as a biocompatible and inert material for a myocardial application. The main advantages of LLCs are mainly related to their easy in situ injection as lamellar phase and their instant in situ transition in the cubic phase. In vivo studies proved the biocompatibility and the inertia of LLCs after their application on the myocardial tissue of mice. In detail, the cardiac activity was monitored through 28 days, and no significant alterations were recorded in the heart anatomy and functionality. Moreover, gross anatomy showed the ability of LLCs to be bio-degraded in a suitable time frame. Overall, these results permitted us to suppose a potential use of LLCs as materials for cardiac drug delivery.

In Situ Swelling Formulation of Glycerol-Monooleate-Derived Lyotropic Liquid Crystals Proposed for Local Vaginal Application

“…A slow and controlled release was recorded, as shown in Figure 8 b, and the trend of the release curve mirrors that of degradation. This suggests that, as in previous studies, the kinetics of release of the lipophilic drug from the cubic phase did not occur by diffusion of the drug first in the aqueous channels and then in the release medium but was probably related to the slow but constant erosion of the matrix [ 34 ]. To investigate the kinetic mechanism involved in drug release from the cubic phase matrix in depth, the data collected during the in vitro release studies were plotted according to four release kinetic models (zero order, first order, Higuchi and Korsmeyer–Peppas) [ 46 ].…”

“…Although LLCs are characterized by a high solubilization capacity for hydrophilic, lipophilic and amphiphilic guest drug molecules [ 6 , 34 ], and during the preparation of samples, no macroscopical sediments or phase separation were observed, a long-term stability test was performed on precursor solutions, either loaded or not with sertaconazole nitrate. The analysis consisted of multiple continuous scans by a laser beam that crossed the formulation from the bottom to the top of a glass vial, which recorded any variations in transmitted and backscattered light.…”

“…The appropriate amount of SVF absorbed by the precursor solution during its transition to a completely swollen cubic phase was determined by gravimetric method, as reported in our previous study [ 34 ], and compared to PBS. Briefly, 1 mL of precursor solution was placed in vial and weighed (M 1 ).…”

A comparison between silicone‐free and silicone‐based emulsions: Technological features and in vivo evaluation

“…Stress sweep tests (1 Hz at 25°C) were carried out with the only purpose of determining the linear viscoelastic region (LVER) in which to operate later [31]. Oscillatory frequency sweep measurements were then performed inside LVER and by setting a frequency range of 0.1–10 Hz and a constant shear stress of 1.0 Pa [32]. The analysis was carried out at 25 ± 1°C [33] and 40 ± 1°C onto two aliquots of the same sample, using a stainless‐steel cone‐plate geometry (diameter 40 mm; angle 2°, gap size of 1 mm) and mechanical parameters such as shear moduli (elastic and viscous components, G′ and G″) and shear viscosity (complex component, ɳ*) were recorded.…”

Alginate-Based Composites for Corneal Regeneration: The Optimization of a Biomaterial to Overcome Its Limits

“…Biocompatibility is commonly recognized as the characteristic of a material fulfilling its biomedical purpose (both therapeutic, reparative and regenerative) without causing unwelcome local or systemic responses in the host and to co-exist in contact with the human body without disturbing the physiological tissue balance of the administration site [ 57 , 58 , 59 , 60 ]. The re-evaluation of this view was well explained by Williams, who reminded us that biocompatibility has to be defined primarily as a function of the application site and the situation in which the material is used [ 61 ].…”