Conventional cancer therapies involve the systemic delivery of anticancer agents that neither discriminate between cancer and normal cells nor eliminate the risk of cancer recurrence. Here, we demonstrate that the combination of gene, drug and phototherapy delivered through a prophylactic hydrogel patch leads, in a colon cancer mouse model, to complete tumour remission when applied to non-resected tumours and to the absence of tumour recurrence when applied following tumour resection. The adhesive hydrogel patch enhanced the stability and provided local delivery of embedded nanoparticles. Spherical gold nanoparticles were used as a first wave of treatment to deliver siRNAs against Kras, a key oncogene driver, and rod-shaped gold nanoparticles mediated the conversion of near-infrared radiation into heat, causing the release of a chemotherapeutic as well as thermally induced cell damage. This local, triple-combination therapy can be adapted to other cancer cell types and to molecular targets associated with disease progression.

Local triple-combination therapy results in tumour regression and prevents recurrence in a colon cancer model

Star polymers: Advances in biomedical applications

In this review, we survey recent literature (2009–2013) on hydrogels that are mechanically tough and adhesive. The impact of published work and trends in the field are examined. We focus on design concepts, new materials, structures related to mechanical performance and adhesion properties. Besides hydrogels made of individual polymers, concepts developed to toughen hydrogels include interpenetrating and double networks, slide ring polymer gels, topological hydrogels, ionically cross-linked copolymer gels, nanocomposite polymer hydrogels, self-assembled microcomposite hydrogels, and combinations thereof. Hydrogels that are adhesive in addition to tough are also discussed. Adhesive properties, especially wet adhesion of hydrogels, are rare but needed for a variety of general technologies. Some of the most promising industrial applications are found in the areas of sensor and actuator technology, microfluidics, drug delivery and biomedical devices. The most recent accomplishments and creative approaches to making tough and sticky hydrogels are highlighted. This review concludes with perspectives for future directions, challenges and opportunities in a continuously changing world.

A review on tough and sticky hydrogels

A review of the designs and prominent biomedical advances of natural and synthetic hydrogel formulations

Bioadhesives are materials frequently used as surgical sealants, though to date, these typically possess limited antibacterial properties. Here, the authors present a novel injectable and antibacterial bioadhesive hydrogel and demonstrate its performance in vivo.

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Injectable bioadhesive hydrogels with innate antibacterial properties

In vitro experiments of a biomaterial's degradability rarely predict its in vivo behaviour. It is now shown that tracking the hydrolytic and enzymatic erosion of model materials by non-invasive fluorescence imaging allows the prediction of in vivo erosion from in vitro data. The approach should enable rapid screening of erodable biomaterials.

In vivo and in vitro tracking of erosion in biodegradable materials using non-invasive fluorescence imaging

Swellable PEG amine/dextran aldehyde composite materials are emerging as a controlled, biocompatible tissue adhesive. We explain how preservation of natural tissue amines provides biocompatibility for PEG/dextran that exceeds the stringent, destructive cyanide-based chemistry of cyanoacrylates, and adhere far better than fibrin glue. Strategic variations of material composition allow for the improvement of biocompatibility and adhesion strength. Material variations can be tailored to match the needs of specific tissue beds for an array of clinical applications. PEG/dextran cohesive properties are most responsive to variations in the PEG component (number of arms and solid content), while tissue/material adhesion strength is primarily determined by the number of aldehydes in the dextran.

Adriana bon Ramos

Papers

In vivo and in vitro tracking of erosion in biodegradable materials using non-invasive fluorescence imaging

Characterization of Star Adhesive Sealants Based On PEG/Dextran Hydrogels

Tuning Adhesion Failure Strength For Tissue-Specific Applications

In vivo and in vitro tracking of erosion in biodegradable materials using non-invasive fluorescence imaging

Tuning adhesion failure strength for tissue-specific applications