Palliative care for oesophageal cancer
Oesophageal cancer is often diagnosed at an advanced stage, hampering potential therapy. Treatment efforts focus on palliative care to improve the quality of life of patients. Since patients with advanced disease suffer from some degree of dysphagia, increasing the risk for eating problems or aspiration, stents are used to restore oesophageal function. Existing metal or plastic stents can cause hyperplastic tissue, tumour ingrowth into the stent and peristalsis. There is only one biodegradable stent available, which degrades over 12 weeks depending on the pH levels in the oesophagus. To optimise the physiochemical and mechanical properties of stents, the EU-funded OSTENT (Novel materials and processing strategy for oesophageal stents) project proposed to develop new materials. One of the aims was to incorporate drugs into the stents, an approach that is widely used in cardiovascular stents. In this context, researchers employed electrospinning technology to synthesise mesh structures based on biodegradable polymers with shape memory properties. They developed a novel technique to produce ceramic nanoparticles of hydroxyapatite and calcium carbonate, and optimised their structure and drug-eluting characteristics. Fillers made from different materials were used to reinforce a number of polymer matrices and then screened for their in vitro degradation properties. Researchers tested various conditions of both acidic and neutral pH to recapitulate the conditions of the lower oesophagus. The mechanical properties of the degraded materials were analysed as were the surfaces using Fourier transform infrared spectroscopy and scanning electron microscopy. The resultant composites proved non-cytotoxic upon interaction with epithelial stem cells in vitro. Overall, the activities of the OSTENT project successfully led to the construction of a novel biodegradable composite stent that could be used in oesophageal and gastrointestinal applications. Although this medical device is far from a therapeutic solution, it offers a solid alternative for palliative care. Furthermore, the technological developments achieved during the project are expected to advance stent construction for cardiovascular, vascular and even neurological applications.
Keywords
Oesophageal cancer, biodegradable stent, OSTENT, electrospinning, ceramic nanoparticles