Local delivery of biocompatible lentinan/chitosan composite for prolonged inhibition of postoperative breast cancer recurrence.

Postsurgical localized chemotherapy for breast cancer recurrence (BCR) still faces many problems which dampen researchers' enthusiasm and discounted prognosis. Simple strategies with controllable toxicities are expected to address these hurdles. Lentinan (LNT) has excellent biocompatibility and notable antitumor activity but rather low bioavailability after intravenous or oral administration. Here, a sponge-like LNT/chitosan composite (LNT/CS sponge) was prepared for efficient local delivery to prevent postoperative BCR. The obtained sponges exhibit uniform porosity and sustained release of LNT in vitro and in vivo. Furthermore, the sponges were implanted and showed significant reduction of postsurgical recurrence and suppression of long-term tumor regrowth with favorable biocompatibility in a subcutaneous postsurgical recurrence mouse model. Subsequent studies revealed that LNT can restrain the stemness of breast cancer cells, which may account for the long-term inhibition of tumor relapse. Therefore, LNT/CS sponge has a great potential as a promising alternative for postsurgical BCR.

Biomimetic Matrix Stiffness Modulates Hepatocellular Carcinoma Malignant Phenotypes and Macrophage Polarization through Multiple Modes of Mechanical Feedbacks.

The extracellular matrix (ECM) stiffening is an important sign of local microenvironment change, which is considered as a hallmark of many diseases including hepatocellular carcinoma (HCC). The fates of both cancer cells and immune cells can be regulated by mechanical feedbacks acquired from ECM, but there is a lack of a precise study of mechanical feedback modes in different cell phenotypes following with the progressively increasing ECM stiffness. Herein, we used a biopolymeric film without further modification of adhesive molecules, as a natural local niche to mimic a gradually stiffening manner from HCC onset in liver cirrhosis to its metastasis in the spinal cord. Three distinct manners of mechanical feedbacks were found: the gradual manner in HCC cell spreading, migration and early apoptosis to oxaliplatin, the stepwise manner in HCC cell adhesion, proliferation, focal adhesion (FA) formation, drug resistance, and macrophage M1 polarization; the specific manner in the stages of the progression of epithelial-mesenchymal transition at different stiffness ranges. Further investigation of molecular mechanisms confirmed those mechanical feedback manners by signaling activation of FA kinase, phosphatidylinositol 3-kinase, and expression of pro-/antiapoptotic and pro-/anti-inflammatory genes. Our results pave a novel avenue to know about mechanical feedbacks from ECM, which could be used for future cancer studies and in vitro drug screening applications.

Immobilized Transforming Growth Factor-Beta 1 in a Stiffness-Tunable Artificial Extracellular Matrix Enhances Mechanotransduction in the Epithelial Mesenchymal Transition of Hepatocellular Carcinoma.

Cancer progression is regulated by multiple factors of extracellular matrix (ECM). Understanding how cancer cells integrate multiple signaling pathways to achieve specific behaviors remains a challenge because of the lack of appropriate models to copresent and modulate ECM properties. Here we proposed a strategy to build a thin biomaterial matrix by poly(l-lysine) and hyaluronan as an artificial stiffness-tunable ECM. Transforming growth factor-beta 1 (TGF-ß1) was used as a biochemical cue to present in an immobilized and spatially controlled manner, with a high loading efficiency of 90%. Either soft matrix with immobilized TGF-ß1 (i-TGF) or bare stiff matrix could only promote HCC cells to form the epithelial phenotype, whereas stiff matrix with i-TGF was the only condition to induce the mesenchymal phenotype. Further investigation revealed that i-TGF increased the specific TGF-ß1 receptor (TßRI) expression to activate PI3K pathway. i-TGF-TßRI interactions also promoted HCC cell adhesion to enlarge contact area for stiffness sensing, resulting in the raising expression of the mechano-sensor (ß1 integrin). Mechanotransduction would then be enhanced by the ß1 integrin/vinculin/p-FAK pathway, leading to a noble PI3K activation. Using our model, a novel mechanism was discovered to elucidate regulation of cell fates by coupling mechanotransduction and biochemical signaling.