Poly(L-lactic acid) (PLLA) is a popular biodegradable polymer, but the accumulated acid production by degradation is a bottleneck for its extended utilization. In this study, chitosan microspheres (CSMs) were introduced into PLLA porous matrices to manipulate the acid microclimate from PLLA degradation. In vitro and in vivo degradation were, respectively, performed in PBS and implanted into rat’s subcutaneous. The results indicated that pH of CSMs/PLLA composites remained stable of around 7.50 in vitro until six weeks. With the increasing of CSMs, mass loss, water absorption of the composites increased, while Mv of PLLA decreased during in vitro test. Furthermore, CSMs/PLLA composites degradation in vivo could be speeded by the introduction of CSMs via obvious morphological destroy under H&E staining observation. These results indicated that incorporation of CSMs not only buffered the acidic microclimate but also improved the degradation of PLLA. The tunable degradation behavior and moderate degradation microclimate of CSMs/PLLA composites developed in the study would provide benefits for its biomedical application.

聚（L-乳酸）（PLLA）是一种流行的可生物降解的聚合物，但是降解产生的累积酸产生是其广泛利用的瓶颈。在这项研究中，将壳聚糖微球（CSM）引入PLLA多孔基质中，以控制PLLA降解引起的酸性微气候。分别在PBS中进行体外和体内降解，然后植入大鼠皮下。结果表明，CSMs / PLLA复合材料的pH值在体外保持稳定在7.50左右，直到六周。随着CSMs的增加，在体外试验中，复合材料的质量损失，吸水率增加，而PLLA的Mv降低。此外，CSM / PLLA复合材料在体内降解通过在H＆E染色观察下明显的形态破坏，可以通过引入CSM来加快速度。这些结果表明掺入CSMs不仅缓冲了酸性微气候，而且还改善了PLLA的降解。研究中开发的CSMs / PLLA复合材料的可调降解行为和中等降解微气候将为其生物医学应用带来好处。