Vat polymerization allows for the accurate and fast fabrication of personalized implants and devices. While the technology advances rapidly and more materials become available, the fabrication of flexible yet tough resorbable materials for biomedical applications remains a challenge. Here, a formulation that can be 3D printed with high accuracy using vat polymerization, yielding materials that are tough, degradable, and non-toxic is presented. This unique combination of properties is obtained by combining a long-chain polycaprolactone macromonomer with a small molecule cross-linker. A wide range of properties is achieved by tuning the ratio of these components. The use of benzyl alcohol as a non-volatile, benign solvent enables fabrication on a lowcost desktop 3D printer, with an exposure time of 8 s per 50-micron layer. The 3D-printed networks are tough and elastic with a tensile strength of 11 MPa at 116% elongation at break. Cells attach and proliferate on the networks with a viability of >91%. The networks are fully degradable to soluble products. This new 3D printable material opens up a range of opportunities in biomedical engineering and personalized medicine.

The anterior segment of the eye is a complex set of structures that collectively act to maintain the integrity of the globe and direct light towards the posteriorly located retina. The eye is exposed to numerous physical and environmental insults such as infection, UV radiation, physical or chemical injuries. Loss of transparency to the cornea or lens (cataract) and dysfunctional regulation of intra ocular pressure (glaucoma) are leading causes of worldwide blindness. Whilst traditional therapeutic approaches can improve vision, their effect often fails to control the multiple pathological events that lead to long-term vision loss. Regenerative medicine approaches in the eye have already had success with ocular stem cell therapy and ex vivo production of cornea and conjunctival tissue for transplant recovering patients’ vision. However, advancements are required to increase the efficacy of these as well as develop other ocular cell therapies. One of the most important challenges that determines the success of regenerative approaches is the preservation of the stem cell properties during expansion culture in vitro. To achieve this, the environment must provide the physical, chemical and biological factors that ensure the maintenance of their undifferentiated state, as well as their proliferative capacity. This is likely to be accomplished by replicating the natural stem cell niche in vitro. Due to the complex nature of the cell microenvironment, the creation of such artificial niches requires the use of bioengineering techniques which can replicate the physico-chemical properties and the dynamic cell–extracellular matrix interactions that maintain the stem cell phenotype. This review discusses the progress made in the replication of stem cell niches from the anterior ocular segment by using bioengineering approaches and their therapeutic implications.

Age-related macular degeneration (AMD) is the leading cause of central blindness in developed countries. It affects people mainly over the age of 50 years. It is a disease of the macula, an area of the retina responsible for sharp central vision. It particularly affects the Bruch’s membrane (BM); a layer in the retina that acts as the basement upon which retinal pigment epithelial cells (RPE) attach and survive. The pathology of AMD is not fully understood, but age is considered the main risk factor. There are two forms; nonexudative, leading to the end-stage of the disease, called nonexudative (or dry) AMD (90% of cases) where fatty deposits called drusen form under the RPE on top of the BM lifting off the RPE, and neovascular (or wet) AMD (10% of cases) where abnormal new blood vessels grow and push through the BM, bleeding in and disrupting the RPE. Neovascular AMD is well controlled with regular antiangiogenic drug injections of anti-vascular endothelial growth factor (anti-VEGF) into the eye, whereas there is no current treatment for nonexudative AMD. Many research groups across the world are working on a treatment for nonexudative AMD. This review discusses the research currently being conducted including cell therapies, development of cell transplantation membranes, targeting other disease structures in affected retina (i.e. drusen), and drug delivery to the retina using nanoparticles. Finally, we include our research contributing to the field; developing a bioactive membrane intended to function two-fold: target diseased structures and transplant healthy RPE to the desired area.