Sequence‐controlled polymerization is the forefront of polymer chemistry. Herein, the feasibility of sequence regulation by using organocatalyzed ring‐opening polymerization (ROP) is demonstrated. In particular, ring expansion strategy is employed to synthesize pre‐organized monomers 1 and 2. ROP is conducted by using 1,5,7‐triazabicyclo[4.4.0]dec‐5‐ene and benzyl alcohol as the catalyst and initiator, respectively. Poly(ester amide)s (PEAs) P1–P3 comprising glycolic acid, lactic acid, and 7‐aminoheptanoic acid units are obtained in high molecular weights and good yields. NMR and matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry results verify the microstructural integrity of P1 and P2. Differential scanning calorimetry results show that PEA without methyl branches is crystalline. Moreover, thermal stability, surface wettability, and degradation profiles of P1–P3 are also investigated.

Synthesis and application of biobased polymers are at the forefront of polymer science. Herein, we report the synthesis, characterization, and functionalization of castor oil-based bioplastics. At first, polymer P1 was synthesized via polyesterification by using monomer 11-bromoundecanoic acid (1) to demonstrate the feasibility of this step-growth polymerization method. The success of this polycondensation technique relies on the high substitution efficiency between terminal groups, carboxylic acid, and carbon-bromide moieties under alkaline conditions. Subsequently, copolymers P2–P5 with varied compositions were obtained by random copolymerization of monomers 1 and 6-bromohexanoic acid (2) in different feed ratios. Linear positive correlation is disclosed between the crystallization (T c) and melting (T m) temperatures of P1–P5 and the molar fraction of 1 within these specimens. Differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD) results illustrate good crystallinity of these bioplastics. Furthermore, the degradation of polymers P1–P5 is propelled by an external basic environment while hindered by their intrinsic hydrophobicity, indicating that alkalinity and composition are two essential factors to manipulate the degradation behaviors of biobased polyesters in the bulk state. Ultimately, polymerization of 1 in the presence of 1-pyrenebutyric acid (3), an end-capping agent, was carried out to yield α-pyrene functionalized polymer P7. This material is capable of serving as a practical fluorescent probe and multiwalled carbon nanotube (MWNT) dispersion stabilizer. Polyesterification reported herein represents a facile and cost-effective synthetic strategy and shows great prospects in sustainable polymer materials.

AIM: To report on the clinical features of patients with retinal amyloid angiopathy (RAA) who were identified to be caused by the transthyretin (TTR) Gly83Arg variant. METHODS: Case series of five patients diagnosed with RAA was collected at Affiliated Hospital of Zunyi Medical University from January 2010 to December 2021. The clinical features, therapeutic strategies, and prognoses of all patients were reviewed. RESULTS: Five patients with a mean age of 52.00±7.23y were diagnosed as RAA. These patients were previously diagnosed with hereditary transthyretin amyloidosis caused by the TTR Gly83Arg variant. Vitreous opacity was found in all 10 eyes, and 7 eyes developed RAA 2 to 20y after the onset of hereditary transthyretin amyloidosis. The clinical manifestations were recurrent vitreous hemorrhage in 2 eyes (29%), neovascular glaucoma in 2 eyes (29%), and iris neovascularization in 1 eye (14%). Microangioma lesions were found in all affected eyes that underwent fundus fluorescein angiography (FFA) in this group of cases, and the incidence of the retinal non-perfusion area was 67%. Although no cases of retinal neovascularization were found, the prognosis of visual acuity was not ideal. CONCLUSION: This is the first report of RAA in patients with the TTR Gly83Arg variant. Complications such as RAA and glaucoma will seriously affect the visual prognosis of patients. Thereafter, regular ophthalmic follow-up of patients with hereditary transthyretin amyloidosis is essential. And FFA after vitrectomy is very important, which can help ophthalmologists detect RAA earlier and treat it in time.