Biomaterial scaffold-based local drug delivery systems for cancer immunotherapy

Immunotherapy has attracted tremendous attention due to the remarkable clinical successes for treating a broad spectrum of tumors. One challenge for cancer immunotherapy is the inability to control localization and sustain concentrations of therapeutics at tumor sites. Local drug delivery systems(LDDSs) like the biomaterial scaffold-based drug delivery systems have emerged as a promising approach for delivering immunotherapeutic agents facilely and intensively in situ with reduced systemic toxicity. In this review, recent advances in biomaterial scaffold-based LDDSs for the administration of immunotherapeutic agents including vaccines, immunomodulators, and immune cells are summarized. Moreover, codelivery systems are also evaluated for local immunotherapy-involving combination anti-tumor therapy,including chemotherapy-immunotherapy, photothermal-immunotherapy, and other combination therapies. Finally, the current challenges and future perspectives on the development of next-generation LDDSs for cancer immunotherapy are discussed.

When starvation therapy meets chemodynamic therapy

In recent years,starvation-primed chemodynamic therapies(ST-CDT)have become a hot topic in the wake of many discoveries related to the aberrant metabolism of cancer cells and their resistance to traditional chemother-apies,as well as altered redox signaling within tumor cells.Nanotechnology platforms are in a unique position to exploit these interrelated phenomena to realize a therapeutic effect;few therapeutic modalities are able to deliver multiple drugs simultaneously outside of nanotechnology,a basic requirement when striving to exploit a complex,interactive system such as a cancer cell.In this review,the pertinent mechanisms of ST and CDT,as well as the important interactions between these two therapies,are discussed.We outline how these therapies may work synergistically or antagonistically,depending on both the therapeutic design and the system of reactions involved.Lastly,specific applications that nanotechnology is particularly well-suited are given,which may offer improvement over clinical state-of-the-art.Such considerations are important,as nanotechnology has historically encountered great difficulty in clinical translation.