Polyhydroxymethylenes as Multifunctional High Molecular Weight Sugar Alcohols Tailored for 3D Printing and Medical Applications

Common sugar alcohols used as artificial sweeteners and components of polymer networks represent low molecular weight polyhydroxymethylenes (PHMs) with the general formula [CH(OH)]_nH₂ but very low degree of polymerization (n = 2–6). Herein high molecular weight PHM (n >> 100) unparalleled in nature is tailored for 3D printing and medical applications by free radical polymerization of 1,3‐dioxol‐2‐one vinylene carbonate to produce polyvinylene carbonate (PVCA) which yields PHM by hydrolysis. Furthermore, PVCA is solution processable and enables PHM functionalization, membrane formation, and extrusion‐based 3D printing. Opposite to cellulose, amorphous PHM is plasticized by water and is readily functionalized via PVCA aminolysis/hydrolysis to produce polyhydroxymethylene urethane (PHMU), enable PHM crosslinking and coupling of PHM with amine‐functional components like gelatin. After hydrolysis/aminolysis the original PVCA shapes are retained. PVCA solution casting yields PVCA and PHM which exhibits uniform and hierarchic pore architectures. Asymmetric membranes, hydrogels, PHM/collagen blends, and electrospun nonwovens of PVCA, PHM, and PHMU are readily tailored for medical applications. 3D printing of PVCA dispersions containing hydroxyapatite affords porous PVCA, PHMU, and PHM scaffolds useful in regenerative medicine. PHM and functionalized PHMs as carbohydrate‐inspired multifunctional materials indicate in vitro biocompatibility and hold great promise for applications in medicine and health care.     

Duodenal necrosis as the presenting manifestation of polyarteritis nodosa

Polyarteritis nodosa involves necrotising vasculitis of small and medium-sized arteries. Multiple organ systems are involved. A non-specific and slow course of disease is common. Gastrointestinal involvement is characterised by abdominal pain, nausea and vomiting. Bowel infarction and perforation, cholecystitis and hepatic infarction are well known complications. However, bowel infarction as the presenting symptom of the disease is rare. The case of a 20-year-old male with necrosis of the duodenum heralding polyarteritis nodosa is reported. The patient made a slow recovery after extensive abdominal surgery and a stormy course. The postoperative management and treatment of polyarteritis nodosa are discussed. A high index of suspicion and prompt multidisciplinary approach are needed in order to improve survival in these rare but potentially fatal conditions. Received: 15 May 2001 / Accepted: 5 February 2002