Preparation of the new peptide drug ACTY116-loaded in situ forming implants and evaluation of its efficacy in pulmonary arterial hypertension and right ventricular hypertrophy induced by SU5416/hypoxia in mice

There is a lack of effective therapeutic drugs for pulmonary arterial hypertension. Previous studies have demonstrated the positive cardiovascular system protective effects of the new peptide ACTY116. However, its stability in ordinary aqueous solution injections is poor and its half-life in the body is short, which has hindered the development of preparations. This study aimed to prepare in situ forming implants (ISFIs) of the peptide ACTY116 and investigate its impact on pulmonary arterial hypertension. We prepared ISFIs using NMP/TA as a solvent and PLGA as a polymer. These ISFIs exhibited low viscosity, low toxicity and sustained release properties. In a mouse model of pulmonary hypertension induced by SU5416/hypoxia, both ISFIs and ACTY116 peptides effectively reduced pulmonary hypertension, cardiac hypertrophy and pulmonary blood vessel wall thickness. In conclusion, this study highlights the potential of ACTY116 as a treatment for pulmonary arterial hypertension and suggests that incorporating it into an in-situ gel implant could be a promising option.