Reduced graphene oxide (rGO) hybridized hydrogel as a near-infrared (NIR)/pH dual-responsive platform for combined chemo-photothermal therapy

For personalized cancer treatment, developing smart biomaterials with multiple biological functions is indispensable in nanomedicine fields. In this work, we developed a highly efficient near-infrared- (NIR-) and pH-responsive carboxymethyl chitosan-functionalized reduced graphene oxide/aldehyde functionalized poly (ethylene glycol) (CMC-rGO/CHO-PEG) hydrogel, which exhibits outstanding delivery performance of antitumor drug, doxorubicin hydrochloride (DOX). CMC was functionalized on the GO nanosheets via a controllable approach in order to achieve strong NIR absorption property and good distribution of rGO. The intercalation effect of CMC-rGO complex improved rGO distribution in the 3D hydrogel, contributing to the enhanced photothermal performance of CMC-rGO/CHO-PEG hydrogel. Furthermore, potential utilization of these CMC-rGO/CHO-PEG hydrogel for drug loading was studied, which provided pH-sensitive release of DOX payload. Particularly, DOX could be released in a more efficient way under acidic environment (pH = 6.5) than that under physiological environment (pH = 7.4). Therefore, this rGO hybridized PEG hydrogel holds strategic potential as a novel drug release platform for combined chem-photothermal therapy.

Multilayered Cultures of NSCLC cells grown at the Air-Liquid Interface allow the efficacy testing of inhaled anti-cancer drugs

Evidence supports the advantages of inhalation over other drug-administration routes in the treatment of lung diseases, including cancer. Although data obtained from animal models and conventional in vitro cultures are informative, testing the efficacy of inhaled chemotherapeutic agents requires human-relevant preclinical tools. Such tools are currently unavailable. Here, we developed and characterized in vitro models for the efficacy testing of inhaled chemotherapeutic agents against non-small-cell lung cancer (NSCLC). These models recapitulated key elements of both the lung epithelium and the tumour tissue, namely the direct contact with the gas phase and the three-dimensional (3D) architecture. Our in vitro models were formed by growing, for the first time, human adenocarcinoma (A549) cells as multilayered mono-cultures at the Air-Liquid Interface (ALI). The in vitro models were tested for their response to four benchmarking chemotherapeutics, currently in use in clinics, demonstrating an increased resistance to these drugs as compared to sub-confluent monolayered 2D cell cultures. Chemoresistance was comparable to that detected in 3D hypoxic tumour spheroids. Being cultured in ALI conditions, the multilayered monocultures demonstrated to be compatible with testing drugs administered as a liquid aerosol by a clinical nebulizer, offering an advantage over 3D tumour spheroids. In conclusion, we demonstrated that our in vitro models provide new human-relevant tools allowing for the efficacy screening of inhaled anti-cancer drugs.

Culturing substrates influence the morphological, mechanical and biochemical features of lung adenocarcinoma cells cultured in 2D or 3D

Alternative models such as three-dimensional (3D) cell cultures represent a distinct milestone towards capturing the realities of cancer biology in vitro and reduce animal experimentation in the preclinical stage of drug discovery. Significant work remains to be done to understand how substrates used in in vitro alternatives influence cancer cells phenotype and drug efficacy responses, so that to accurately link such models to specific in vivo disease scenarios. Our study describes how the morphological, mechanical and biochemical properties of adenocarcinoma (A549) cells change in response to a 3D environment and varying substrates. Confocal Laser Scanning (LSCM), He-Ion (HIM) and Atomic Force (AFM) microscopies, supported by ELISA and Western blotting, were used. These techniques enabled us to evaluate the shape, cytoskeletal organization, roughness, stiffness and biochemical signatures of cells grown within soft 3D matrices (PuraMatrix™ and Matrigel™), and to compare them to those of cells cultured on two-dimensional glass substrates. Cell cultures are also characterized for their biological response to docetaxel, a taxane-type drug used in Non-Small-Cell Lung Cancer (NSCLC) treatment. Our results offer an advanced biophysical insight into the properties and potential application of 3D cultures of A549 cells as in vitro alternatives in lung cancer research.

Surface Patterning of Gold Nanoparticles on PEG-Based Hydrogels to Control Cell Adhesion

We report on a versatile and easy approach to micro-pattern gold nanoparticles (Au NPs) on 8-arm poly(ethylene glycol)-vinyl sulfone thiol (8PEG-VS-SH) hydrogels, and the application of these patterned Au NPs stripes in controlling cell adhesion. Firstly, the Au NPs were patterned on silicon wafers, and then they were transferred onto reactive, multifunctional 8PEG-VS-SH hydrogels. The patterned, micrometer-sized Au NPs stripes with variable spacings ranging from 20 μm to 50 μm were created by our recently developed micro-contact deprinting method. For this micro-contact deprinting approach, four different PEG-based stamp materials have been tested and it was found that the triblock copolymer PEG-PPG-PEG-(3BC) stamp established the best transfer efficiency and has been used in the ongoing work. After the successful creation of micro-patterns of Au NPs stripes on silicon, the patterns can be transferred conveniently and accurately to 8PEG-VS-SH hydrogel films. Subsequently these Au NPs patterns on 8PEG-VS-SH hydrogels have been investigated in cell culture with murine fibroblasts (L-929). The cells have been observed to adhere to and spread on those nano-patterned micro-lines in a remarkably selective and ordered manner.

Geometric Control of Cell Alignment and Spreading within the Confinement of Antiadhesive Poly(Ethylene Glycol) Microstructures on Laser-Patterned Surfaces

In this study, a mask-less laser-assisted patterning method is used to fabricate well-defined cell-adhesive microdomains delimited by protein-repellent poly(ethylene glycol) (PEG) microstructures prepared from multiarm (8-PEG) macromonomers. The response of murine fibroblasts (L-929) toward these microdomains is investigated, revealing effective cell confinement within the cell-adhesive areas surrounded by nonadhesive 8-PEG microstructures. Moreover, the spatial positioning of cells in microdomains of various sizes and geometries is analyzed, indicating control of cell density, size, and elongated cell shape induced by the size of the microdomains and the geometric confinement.