This review presents the recent developments in the research hotspots of advanced functional polymers; their concepts, design strategies, and applications are briefly discussed.

Silk-based nanoparticles have been exhibiting an increasing potential for use as drug delivery systems due to their great versatility. To extend applications of silk sericin in nanomedicine and improve the performance of silk-based nanoparticles in drug delivery, a facile two-step cross-linking is attempted, for the first time, to fabricate surface charge-reversal silk sericin-based nanoparticles (SSC@NPs) by introducing chitosan into silk sericin. The results suggest stable SSC@NPs are formed with a negative surface charge in a neutral environment. Under mildly acidic conditions, however, surface charge of SSC@NPs undergoes a negative-to-positive conversion. It proves that pH can regulate surface charge of SSC@NPs. It is the increased amino/carboxyl ratio in SSC@NPs that explains the underlying mechanism of the charge conversion property of SSC@NPs. Furthermore, the positively charged SSC@NPs triggered by tumor acidic microenvironment (pH 6.0) result in a 6.0fold higher cellular uptake than the negatively charged counterparts at pH 7.4. In addition, an anticancer drug doxorubicin (DOX) is readily loaded into SSC@NPs and released in a pH-dependent manner. This work provides a simple method to fabricate smart pH-responsive nanoparticles for anticancer drug delivery.

Transdermal drug delivery exhibited encouraging prospects, especially through superficial drug administration routes. However, only a few limited lipophilic drug molecules could cross the skin barrier, those are with low molecular weight and rational Log P value.Microneedles (MNs) can overcome these limitations to deliver numerous drugs into the dermal layer by piercing the outermost skin layer of the body. In the case of superficial cancer treatments, topical drug administration faces severely low transfer efficiency, and systemic treatments are always associated with side effects and premature drug degradation. MN-based systems have achieved excellent technical capabilities and been tested for pre-clinical chemotherapy, photothermal therapy, photodynamic therapy, and immunotherapy. In this review, we will focus on the features, progress, and opportunities of MNs in the anticancer drug delivery system. Then, we will discuss the strategies and advantages in these works and summarize challenges, perspectives, and translational potential for future applications.

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Transforming growth factor-beta 1 (TGF-β1) plays a central role in hepatic progenitor cells- (HPCs-) mediated liver repair and fibrosis. However, different effects of TGF-β1 on progenitor cells have not been described. In this study, both in vitro (HPCs cocultured with hepatic stellate cells (HSCs) in transwells) and in vivo (CCl4-injured liver fibrosis rat) systems were used to evaluate the impacts. We found that HPCs pretreated with TGF-β1 for 12 hours inhibited the activation of HSCs, while sensitization for 48 hours increased the activation of HSCs. Consistent with these in vitro results, the in vivo fibrosis rat model showed the same time-dependent dual effect of TGF-β1. Regression of liver fibrosis as well as normalization of serum aminotransferase and albumin levels was detected in the rats transplanted with HPCs pretreated with TGF-β1 for 12 hours. In contrast, severe liver fibrosis and elevated collagen-1 levels were detected in the rats transplanted with HPCs pretreated with TGF-β1 for 48 hours. Furthermore, the TGF-β1-pretreated HPCs were shown to deactivate HSCs via enhancing SERPINE1 expression. Inhibition of SERPINE1 reversed the deactivation response in a dose-dependent manner.