The ability to trigger changes to material properties with external stimuli, so‐called “smart” behavior, has enabled novel technologies for a wide range of healthcare applications. Response to small changes in temperature is particularly attractive, where material transformations may be triggered by contact with the human body. Thermoreversible gelators are materials where warming triggers reversible phase change from low viscosity polymer solution to a gel state. These systems can be generated by the exploitation of macromolecules with lower critical solution temperatures included in their architectures. The resultant materials are attractive for topical and mucosal drug delivery, as well as for injectables. In addition, the materials are attractive for tissue engineering and 3D printing. The fundamental science underpinning these systems is described, along with progress in each class of material and their applications. Significant opportunities exist in the fundamental understanding of how polymer chemistry and nanoscience describe the performance of these systems and guide the rational design of novel systems. Furthermore, barriers to translating technologies must be addressed, for example, rigorous toxicological evaluation is rarely conducted. As such, applications remain tied to narrow fields, and advancements will be made where the existing knowledge in these areas may be applied to novel problems of science.

PNIPAM98–PEG122–PNIPAM98 is explored as a thermoreversible gelator for topical administration, giving temperature-dependent release of progesterone over up to 6 days.

Thermoreversible gels switch from a free‐flowing liquid state to an elastic gel mesophase upon warming, displaying the reverse transition upon cooling. While this phenomenon makes these advanced materials highly attractive in numerous fields, the generation of optimal materials of tailored rheology and transition temperatures is stifled by the lack of design principles. To address this need, a library of ABA copolymers has been prepared with “A” blocks exhibiting thermoresponsive behavior and “B” blocks of poly(ethylene glycol). This library evaluates the effect of “A” chemistry, probing three polymer classes, and A/B block molecular weight on thermally‐induced phase changes in solutions of the polymers. An exploration by rheometry coupled to Small‐Angle Neutron Scattering (SANS) elucidates temperature‐dependent hierarchical self‐assembly processes occurring on the nanoscale as well as bulk rheology. This process deciphered links between rheology and supracolloidal assemblies (sphere, ellipses, and cylinders) within the gel state with interactions probed further via structure factors. Several design principles are identified to inform the genesis of next‐generation thermoreversible gels, alongside novel materials exhibited thermoresponsive behavior in the solution state for use in applied healthcare technologies.

Three-dimensional (3D) printing enhances the production of on-demand fabrication of patient-specific devices 27 as well as anatomically fitting implants with high complexity in a cost-effective manner. Additive systems that 28 employ vat photopolymerisation such as stereolithography (SLA) and digital light projection (DLP) are used 29 widely in the field of biomedical science and engineering. However, additive manufacturing methods can be 30 limited by the types of materials that can be used. In this study, we present an isosorbide-based formulation for a 31 polymer resin yielding a range of elastic moduli between 1.7-3 GN/mm 2 dependent on the photoinitiator system 32 used as well as the amount of calcium phosphate filler added. The monomer was prepared and enhanced for 3D-33 printing using an SLA technique that delivered stable and optimized 3D-printed models. The resin discussed could 34 potentially be used following major surgery for the correction of congenital defects, the removal of oral tumours 35 and the reconstruction of the head and neck region. The surgeon is usually limited with devices available to restore 36 both function and appearance and with the ever-increasing demand for low-priced and efficient facial implants, 37 there is an urgent need to advance new manufacturing approaches and implants with a higher osseointegration 38 performance. 39 40 42 and skin, as well as essential supporting structures such as blood vessels and nerves [1]. There are approximately 43 60,000 craniofacial reconstruction surgeries carried out each year in the UK alone [2]. These operations are needed 44 as a result of trauma, such as road traffic accidents, surgery to remove tumours or to correct congenital anomalies 45 in babies and children born with conditions such as cleft lip and palate. In some cases, the reconstructive surgery 46 is needed to correct functional issues, such as creating more space inside the skull to enable a person's brain to 47 grow or even to provide better protection for their eyes. Oral and maxillofacial surgery specialises in treating 48 many conditions and diseases in the head, neck, face and jaw region [3]. With the ever-growing demand for a 49 suitable material to restore both function and appearance for patients there have been developments taking place 50 in the field of dental materials to best suit the ideal selection criteria to satisfy the functionality, biocompatibility, 51 aesthetics, durability and ease of manipulation and contourability as a maxillofacial material. Due to excellent 52 osseointegration and osteogenesis properties, autologous bone grafts remain a gold standard technique for surgery 53 in this area [4]. However, the use of autologous bone grafts has disadvantages such as the risk of infection, risk 54 of rejection and multiple operations, which lead to postoperative pain and discomfort for patients. 55

Correction for ‘Poly(N-isopropyl acrylamide)–poly(ethylene glycol)–poly(N-isopropyl acrylamide) as a thermoreversible gelator for topical administration’ by P. Haddow et al., Mater. Adv., 2020, 1, 371–386, DOI: 10.1039/D0MA00080A.