Targeting PIN1 exerts potent antitumor activity in pancreatic ductal carcinoma via inhibiting tumor metastasis.

The human prolyl isomerase PIN1, best known for its association with carcinogenesis, has recently been indicated in the disease of pancreatic ductal adenocarcinoma (PDAC). However, the functions of PIN1 and the feasibility of targeting PIN1 in PDAC remain elusive. For this purpose, we examined the expression of PIN1 in cancer, related paracarcinoma and metastatic cancer tissues by immunohistochemistry and analyzed the associations with the pathogenesis of PDAC in 173 patients. The functional roles of PIN1 in PDAC were explored in vitro and in vivo using both genetic and chemical PIN1 inhibition. We showed that PIN1 was upregulated in pancreatic cancer and metastatic tissues. High PIN1 expression is significantly association with poor clinicopathological features and shorter overall survival and disease-free survival. Further stratified analysis showed that PIN1 phenotypes refined prognostication in PDAC. Inhibition of PIN1 expression with RNA interference or with all trans retinoic acid decreased not only the growth but also the migration and invasion of PDAC cells through regulating the key molecules of multiple cancer-driving pathways, simultaneously resulting in cell cycle arrest and mesenchymal-epithelial transition in vitro. Furthermore, genetic and chemical PIN1 ablation showed dramatic inhibition of the tumorigenesis and metastatic spread and then reduced the tumor burden in vivo. We provided further evidence for the use of PIN1 as a promising therapeutic target in PDAC. Genetic and chemical PIN1 ablation exerted potent antitumor effects through blocking multiple cancer-driving pathways in PDAC. More potent and specific PIN1 targeted inhibitors could be exploited to treat this aggressive cancer.

Highly Porous Microcarriers for Minimally Invasive In Situ Skeletal Muscle Cell Delivery.

Microscale cell carriers have recently garnered enormous interest in repairing tissue defects by avoiding substantial open surgeries using implants for tissue regeneration. In this study, the highly open porous microspheres (HOPMs) are fabricated using a microfluidic technique for harboring proliferating skeletal myoblasts and evaluating their feasibility toward cell delivery application in situ. These biocompatible HOPMs with particle sizes of 280-370 µm possess open pores of 10-80 µm and interconnected paths. Such structure of the HOPMs conveniently provide a favorable microenvironment, where the cells are closely arranged in elongated shapes with the deposited extracellular matrix, facilitating cell adhesion and proliferation, as well as augmented myogenic differentiation. Furthermore, in vivo results in mice confirm improved cell retention and vascularization, as well as partial myoblast differentiation. These modular cell-laden microcarriers potentially allow for in situ tissue construction after minimally invasive delivery providing a convenient means for regeneration medicine.

Pin1 inhibition potently suppresses gastric cancer growth and blocks PI3K/AKT and Wnt/ß-catenin oncogenic pathways.

Gastric cancer is the second leading cause of cancer-related mortality and the fourth most common cancer globally. High intratumor heterogeneity of advanced gastric cancer poses great challenges to targeted therapy due to simultaneous activation of many redundant cancer-driving pathways. A central common signaling mechanism in cancer is proline-directed phosphorylation, which is further regulated by the unique proline isomerase Pin1. Pin1 inhibition exerts anticancer activity by blocking multiple cancer-driving pathways in some cancers, but its role in gastric cancer is not fully understood. Here we detected Pin1 protein expression in 1065 gastric cancer patients and paired normal tissues using immunohistochemistry and Western blot, and then examined the effects of Pin1 overexpression, and genetic and chemical Pin1 inhibition using Pin1 short hairpin RNA or small molecule inhibitor all-trans retinoic acid (ATRA) on tumorigenesis of human gastric cancer in vitro and in vivo, followed by biochemical analyses to elucidate Pin1 regulated oncogenic pathways. We found that Pin1 was significantly overexpressed in primary and metastasized tumors, with Pin1 overexpression being correlated with advanced stage and poor prognosis. Furthermore, whereas Pin1 overexpression promoted the transformed phenotype in immortalized and nontransformed human gastric cells, either genetic or chemical Pin1 inhibition in multiple human gastric cancer cells potently suppressed cell growth, G1/S transition and colony formation in vitro, as well as tumor growth in xenograft tumor models in vivo, which were further supported by downregulation of multiple key oncoproteins in PI3K/AKT and Wnt/ß-catenin signaling pathways. These results not only provide the first evidence for a critical role of Pin1 in the tumorigenesis of gastric cancer but also suggest that targeting Pin1 using ATRA or other inhibitors offers an effective new therapeutic approach for treating advanced gastric cancer.

Nanocarrier of Pin1 inhibitor based on supercritical fluid technology inhibits cancer metastasis by blocking multiple signaling pathways.

Cancer metastasis is the primary cause of all cancer-related deaths due to the lack of effective targeted drugs that simultaneously block multiple signaling pathways that drive the dissemination and growth of cancer cells. The unique proline isomerase Pin1 activates numerous cancer pathways, but its role in cancer metastasis and the inhibitory efficacy of Pin1 inhibitors on cancer metastasis are unknown. Moreover, the applicability of Pin1 inhibitor-all-trans retinoic acid (ATRA) is limited due to its several drawbacks. Herein, uniform ATRA-loaded polylactic acid-polyethylene glycol block copolymer nanoparticles (ATRA-NPs) with high encapsulation efficiency, good cellular uptake, excellent controlled release performance and pharmacokinetics are developed using supercritical carbon dioxide processing combined with an optimized design. ATRA-NPs exhibited excellent biosafety and significant inhibition on the growth and metastasis of hepatocellular carcinoma. Pin1 played a key role in cancer metastasis and was the main target of ATRA-NPs. ATRA-NPs exerted their potent anti-metastatic effect by inhibiting Pin1 and then simultaneously blocking multiple signaling pathways and cancer epithelial-mesenchymal progression. Since ATRA-NPs could effectively couple the inhibition of cancer cell dissemination with cancer growth, it provided a novel therapeutic strategy for efficiently inhibiting cancer metastasis.

Cancer Cytomembrane-Cloaked Prussian Blue Nanoparticles Enhance the Efficacy of Mild-Temperature Photothermal Therapy by Disrupting Mitochondrial Functions of Cancer Cells.

Despite its success against cancer, photothermal therapy (PTT) (>50 °C) suffers from several limitations such as triggering inflammation and facilitating immune escape and metastasis and also damage to the surrounding normal cells. Mild-temperature PTT has been proposed to override these shortcomings. We developed a nanosystem using HepG2 cancer cell membrane-cloaked zinc glutamate-modified Prussian blue nanoparticles with triphenylphosphine-conjugated lonidamine (HmPGTL NPs). This innovative approach achieved an efficient mild-temperature PTT effect by downregulating the production of intracellular ATP. This disrupts a section of heat shock proteins that cushion cancer cells against heat. The physicochemical properties, anti-tumor efficacy, and mechanisms of HmPGTL NPs both in vitro and in vivo were investigated. Moreover, the nanoparticles cloaked with the HepG2 cell membrane substantially prolonged the circulation time in vivo. Overall, the designed nanocomposites enhance the efficacy of mild-temperature PTT by disrupting the production of ATP in cancer cells. Thus, we anticipate that the mild-temperature PTT nanosystem will certainly present its enormous potential in various biomedical applications.

Minimally invasive co-injection of modular micro-muscular and micro-vascular tissues improves in situ skeletal muscle regeneration.

Various conventional treatment strategies for volumetric muscle loss (VML) are often hampered by the extreme donor site morbidity, the limited availability of quality muscle flaps, and complicated, as well as invasive surgical procedures. The conventional biomaterial-based scaffolding systems carrying myoblasts have been extensively investigated towards improving the regeneration of the injured muscle tissues, as well as their injectable forms. However, the applicability of such designed systems has been restricted due to the lack of available vascular networks. Considering these facts, here we present the development of a unique set of two minimally invasively injectable modular microtissues, consisting of mouse myoblast (C2C12)-laden poly(lactic-co-glycolic acid) porous microspheres (PLGA PMs), or the micro-muscles, and human umbilical vein endothelial cell (HUVEC)-laden poly(ethylene glycol) hollow microrods (PEG HMs), or the microvessels. Besides systematic in vitro investigations, the myogenic performance of these modular composite microtissues, when co-injected, was explored in vivo using a mouse VML model, which confirmed improved in situ muscle regeneration and remolding. Together, we believe that the construction of these injectable modular microtissues and their combination for minimally invasive therapy provides a promising method for in situ tissue healing.

Synergistic antitumor efficacy of doxorubicin and gambogic acid-encapsulated albumin nanocomposites.

Despite the success, the applicability of traditional chemotherapy still faces several challenges in treating cancer-related ailments, such as enormous toxicity and adverse effects. Combinatorial chemotherapy at reduced doses can offer augmented therapeutic efficiency through multiple mechanisms and even substantially circumvents the issues of toxicity and adverse effects. To demonstrate these facts, herein, two kinds of antitumor drugs, doxorubicin (DOX) and gambogic acid (GA), are encapsulated in bovine serum albumin (BSA) nanoparticles distinctly, resulting in DNP and GNP, respectively. These drug-loaded albumin nanocomposites, DNPs, and GNPs, showed a synergistic effect in ablating HepG2 tumor cells at a combination index (CI) of 0.38. Further, the ex vivo fluorescence imaging investigation confirmed the enriched drug internalization in the tumor precisely, which could be due to the enhanced permeation and retention (EPR) effect, resulting in the augmented therapeutic efficiency of designed nanoformulation. Notably, the synergistic tumor inhibition efficacy is more significantly attained at a 3-fold lesser dose of combined treatment than that of single full dose treatment in vivo. As anticipated, these conditions resulted in reduced organ toxicity. Together, this combinatorial strategy using BSA-based composites is an appropriate approach for application in medicine.

Biodegradable Quantum Composites for Synergistic Photothermal Therapy and Copper-Enhanced Chemotherapy.

In recent times, the combination therapy has garnered enormous interest owing to its great potential in clinical research. It has been reported that disulfiram, a clinical antialcoholism drug, could be degraded to diethyldithiocarbamate (DDTC) in vivo and subsequently result in the copper-DDTC complex (Cu(DDTC)2) toward ablating cancer cells. In addition, the ultrasmall copper sulfide nanodots (CuS NDs) have shown great potential in cancer treatment because of their excellent photothermal and photodynamic therapeutic efficiencies. Herein, by taking advantage of the interactions between CuS and DDTC, a new multifunctional nanoplatform based on DDTC-loaded CuS (CuS-DDTC) NDs is successfully fabricated, leading to the achievement of the synergistic effect of photothermal and copper enhanced chemotherapy. All experimental results verified promising synergistic therapeutic effects. Moreover, in vivo biocompatibility and metabolism experiments displayed that the CuS-DDTC NDs could be quickly excreted from the body with no apparent toxicity signs. Together, our findings indicated the superior synergistic therapeutic effect of photothermal and copper-enhanced chemotherapy, providing a promising anticancer strategy based on the CuS-DDTC NDs drug delivery system.

Near-Infrared-Activated Lysosome Pathway Death Induced by ROS Generated from Layered Double Hydroxide-Copper Sulfide Nanocomposites.

The overdeveloped lysosomes in cancer cells are gaining increasing attention toward more precise and effective organelle-targeted cancer therapy. It is suggested that rod/plate-like nanomaterials with an appropriate size exhibited a greater quantity and longer-term lysosomal enrichment, as the shape plays a notable role in the nanomaterial transmembrane process and subcellular behaviors. Herein, a biodegradable platform based on layered double hydroxide-copper sulfide nanocomposites (LDH-CuS NCs) is successfully prepared via in situ growth of CuS nanodots on LDH nanoplates. The as-prepared LDH-CuS NCs exhibited not only high photothermal conversion and near-infrared (NIR)-induced chemodynamic and photodynamic therapeutic efficacies, but also could achieve real-time in vivo photoacoustic imaging (PAI) of the entire tumor. LDH-CuS NCs accumulated in lysosomes would then generate extensive subcellular reactive oxygen species (ROS) in situ, leading to lysosomal membrane permeabilization (LMP) pathway-associated cell death both in vitro and in vivo.

Bioinspired red blood cell membrane-encapsulated biomimetic nanoconstructs for synergistic and efficacious chemo-photothermal therapy.

Recently, the fabrication of nanotechnology-based co-delivery systems has garnered enormous interest for efficacious cancer therapy. However, these systems still face certain challenges such as codelivery of drugs with different chemistries, inadequate loading efficiency, immune rejection resulting in rapid clearance and substantially poor bioavailability in vivo. To address the challenges, we have developed a biomimetic and stable design based on bovine serum albumin (BSA) nanoparticles that are encapsulated with a hydrophilic photothermal agent, indocyanine green (ICG), as well as a hydrophobic agent, gambogic acid (GA), via the desolvation method. Furthermore, these nanoconstructs have been coated with the red blood cell membranes (RBCm), which exhibit pronounced long-term circulation in addition to avoiding premature leakage of drugs. RBCm-coated BSA nanoparticles show a higher affinity towards both GA and ICG (RmGIB NPs), resulting in high loading efficiencies of 24.3 ±â€¯1.2 % and 25.0 ±â€¯1.2 %, respectively. Moreover, the bio-efficacy investigations of these biomimetic constructs (RmGIB NPs) in cells in vitro as well as in tumor-bearing mice in vivo confirm augmented inhibition, demonstrating potential synergistic chemo-photothermal therapeutic efficacy. Altogether, we provide an efficient delivery platform for designing and constructing BSA nanovehicles toward synergistic and effective co-delivery of therapeutics.

PIN1 Inhibition Sensitizes Chemotherapy in Gastric Cancer Cells by Targeting Stem Cell-like Traits and Multiple Biomarkers.

Gastric cancer is the third leading cause of cancer-related death worldwide. Diffuse type gastric cancer has the worst prognosis due to notorious resistance to chemotherapy and enrichment of cancer stem-like cells (CSC) associated with the epithelial-to-mesenchymal transition (EMT). The unique proline isomerase PIN1 is a common regulator of oncogenic signaling networks and is important for gastric cancer development. However, little is known about its roles in CSCs and drug resistance in gastric cancer. In this article, we demonstrate that PIN1 overexpression is closely correlated with advanced tumor stages, poor chemo-response and shorter recurrence-free survival in diffuse type gastric cancer in human patients. Furthermore, shRNA-mediated genetic or all-trans retinoic acid-mediated pharmaceutical inhibition of PIN1 in multiple human gastric cancer cells potently suppresses the EMT, cell migration and invasion, and lung metastasis. Moreover, PIN1 genetic or pharmaceutical inhibition potently eliminates gastric CSCs and suppresses their self-renewal and tumorigenicity in vitro and in vivo Consistent with these phenotypes, are that PIN1 biochemically targets multiple signaling molecules and biomarkers in EMT and CSCs and that genetic and pharmaceutical PIN1 inhibition functionally and drastically enhances the sensitivity of gastric cancer to multiple chemotherapy drugs in vitro and in vivo These results demonstrate that PIN1 inhibition sensitizes chemotherapy in gastric cancer cells by targeting CSCs, and suggest that PIN1 inhibitors may be used to overcome drug resistance in gastric cancer.

Endothelialized microrods for minimally invasive in situ neovascularization.

Despite the significant advancements in fabricating various scaffolding systems over the past decades, generation of functional tissues towards vascularization remains challenging for the currently available biofabrication approaches. On the other hand, the applicability of traditional surgical transplantation of vascularized tissue constructs is sometimes limited due to the sophisticated surgical procedures, which are invasive, leading to increased risks of scar formation and infection. Considering these facts, we present an innovative platform, the angiogenic microrods composed of sodium alginate/gelatin harboring proliferating endothelial cells using a specially designed double T-junction microfluidic device with an expansion chamber, for achieving minimally invasive neovascularization in situ. Such vessel-like microarchitectures could be derived through controlled penetration of the crosslinker genepin for the gelatin phase, ensuing differential degrees in crosslinking of peripheral and central portions of the microstructures, thus resulting in the formation of vascular lumen-like hollow cavities via endothelial cell migration and proliferation during culture in vitro. Furthermore, in vivo performance of the microrods was explored. We believe that the development of these modular microrods for minimally invasive delivery is of great interest and offers a convenient approach for vascularization in situ.

Supercritical Fluid-Assisted Porous Microspheres for Efficient Delivery of Insulin and Inhalation Therapy of Diabetes.

Pulmonary delivery of drugs has attracted increasing attention in healthcare, as the lungs are an easily accessible site for noninvasive systemic delivery of drugs. Although pulmonary inhalation of porous microparticles has been shown to sustain drug delivery, there are limited reports on efficient delivery of insulin and inhalation therapy of diabetes based on supercritical carbon dioxide (SC-CO2 ) technology. Herein, this study reports the fabrication of insulin-loaded poly-l-lactide porous microspheres (INS-PLLA PMs) by using the SC-CO2 technology, and their use as an inhalation delivery system potentially for diabetes therapy. Biocompatibility and delivery efficiency of the PLLA PMs in the lungs are investigated. The PLLA PMs show negligible toxicity to lung-derived cells, resulting in no significant reduction in cell viability, as well as levels of various inflammatory mediators such as interleukin (IL)-6, IL-8, and tumor necrosis factor-α, compared with the negative control group. INS-PLLA PMs are further efficiently deposited in the trachea and the bronchi of superior lobes of the lungs, which exhibit pronounced hypoglycemic activity in induced diabetic rats. Together, the results demonstrate that the INS-PLLA PMs have a strong potential as an effective strategy for inhalation treatment of diabetes.

Pin1 inhibition reverses the acquired resistance of human hepatocellular carcinoma cells to Regorafenib via the Gli1/Snail/E-cadherin pathway.

Hepatocellular carcinoma (HCC) is the second leading cancer death because of its high metastasis and drug resistance. Regorafenib was newly approved by FDA for HCC treatment, but its resistance is not understood. The unique isomerase Pin1 is critical for HCC development, but its role in metastasis and drug resistance is unknown. Here we generated Regorafenib-resistant HCC cells and found that they exhibited enhanced tumor invasion and metastasis in vitro and in vivo, and elevated Pin1 levels. Furthermore, Pin1 was highly overexpressed and closely related to the EMT in human HCC tissues. Depletion or overexpression of Pin1 correspondingly inhibited or promoted HCC cell migration and invasion, with altered expression of EMT-related molecules, E-cadherin and Snail. Significantly, Pin1 interacted with Gli1, a regulator of the EMT, and silencing Gli1 partly blocked Pin1-induced EMT in HCC cells. Moreover, genetic or chemical Pin1 inhibition reversed Regorafenib resistance of HCC with reducing EMT, migration, invasion and metastasis in vitro and in vivo. These results reveal a novel molecular mechanism underlying Regorafenib resistance in HCC, and also provide first evidence that Pin1 inhibitors offer an attractive strategy for treating Regorafenib-resistant HCC.

Polyaniline/Carbon Nanotubes Composite Modified Anode via Graft Polymerization and Self-Assembling for Microbial Fuel Cells.

Microbial fuel cells (MFCs) are promising devices for sustainable energy production, wastewater treatment and biosensors. Anode materials directly interact with electricigens and accept electrons between cells, playing an important role in determining the performance of MFCs. In this study, a novel carbon nanotubes (CNTs) and polyaniline (PANI) nanocomposite film modified Indium-tin oxide (ITO) anode was fabricated through graft polymerization of PANI after the modification of γ-aminopropyltriethoxysilane (APTES) on ITO substrate, which was followed by layer-by-layer (LBL) self-assembling of CNTs and PANI alternatively on its surface. (CNTs/PANI)n/APTES/ITO electrode with low charge transfer resistance showed better electrochemical behavior compared to the bare ITO electrode. Twelve layers of CNTs/PANI decorated ITO electrode with an optimal nanoporous network exhibited superior biocatalytic properties with a maximal current density of 6.98 µA/cm², which is 26-fold higher than that of conventional ITO electrode in Shewanella loihica PV-4 bioelectrochemical system. MFCs with (CNTs/PANI)12/APTES/ITO as the anode harvested a maximum output power density of 34.51 mW/m², which is 7.5-fold higher than that of the unmodified ITO electrode. These results demonstrate that (CNTs/PANI)12/APTES/ITO electrode has superior electrochemical and electrocatalytic properties compared to the bare ITO electrode, while the cellular toxicity of CNTs has an effect on the performance of MFC with (CNTs/PANI)n/APTES/ITO electrode.

A high-throughput study on endothelial cell adhesion and growth mediated by adsorbed serum protein via signaling pathway PCR array.

The purpose of this paper is to utilize the signaling pathway polymerase chain reaction (PCR) arrays to investigate the activation of two important biological signaling pathways in endothelial cell adhesion and growth mediated by adsorbed serum protein on the surface of bare and titanium nitride (TiN)-coated nickel titanium (NiTi) alloys. First, the endothelial cells were cultured on the bare and TiN-coated NiTi alloys and chitosan films as control for 4 h and 24 h, respectively. Then, the total RNA of the cells was collected and the PCR arrays were performed. After that, the differentially expressed genes in the transforming growth factor beta (TGF-ß) signaling pathway and the regulation of actin cytoskeleton pathway were screened out; and the further bioinformatics analyses were performed. The results showed that both TGF-ß signaling pathway and regulation of actin cytoskeleton pathway were activated in the cells after 4 h and 24 h culturing on the surface of bare and TiN-coated NiTi alloys compared to the chitosan group. The activated TGF-ß signaling pathway promoted cell adhesion; the activated regulation of actin cytoskeleton pathway promoted cell adhesion, spreading, growth and motility. In addition, the activation of both pathways was much stronger in the cells cultured for 24 h versus 4 h, which indicated that cell adhesion and growth became more favorable with longer time on the surface of two NiTi alloy materials.

Supercritical Fluid-Assisted Decoration of Nanoparticles on Porous Microcontainers for Codelivery of Therapeutics and Inhalation Therapy of Diabetes.

The impact of nanotechnology and its advancements have allowed us to explore new therapeutic modalities. To this end, we designed nanoparticles-inlaid porous microparticles (NIPMs) coloaded with small interfering RNA (siRNA) and glucagon-like peptide-1 (GLP-1) using the supercritical carbon dioxide (SC-CO2) technology as an inhalation delivery system for diabetes therapy. siRNA-encapsulating chitosan (CS) nanoparticles were first synthesized by an ionic gelation method, which resulted in particles with small sizes (100-150 nm), high encapsulation efficiency (∼94.8%), and sustained release performance (∼60% in 32 h). These CS nanoparticles were then loaded with GLP-1-dispersed poly-l-lactide (PLLA) porous microparticles (PMs) by SC-CO2-assisted precipitation with the compressed antisolvent (PCA) process. The hypoglycemic efficacy of NIPMs administered via pulmonary route in mice persisted longer due to sustained release of siRNA from CS nanoparticles and the synergistic effects of GLP-1 in PMs, which significantly inhibited the expression of dipeptidyl peptidase-4 mRNA (DPP-4-mRNA). This ecofriendly technology provides a convenient way to fabricate nanoparticle-microparticle composites for codelivery of a gene and a therapeutic peptide, which will potentially find widespread applications in the field of pharmaceutics.

Supercritical Fluid-Assisted Fabrication of Indocyanine Green-Encapsulated Silk Fibroin Nanoparticles for Dual-Triggered Cancer Therapy.

Despite the success and advantages over traditional chemotherapeutic strategies, photothermal therapy (PTT) suffers from certain limitations, such as poor stability, low therapeutic efficacy of PTT agents in vivo, and their affinity loss during the multistep synthesis process of delivery carriers, among others. To address these limitations, we designed a stable, biocompatible, and dual-triggered formulation of indocyanine green (ICG)-encapsulated silk fibroin (SF) (ICG-SF) nanoparticles using supercritical fluid (SCF) technology. We demonstrated that ICG encapsulation in SF through this environmental-friendly approach has offered excellent photothermal stability, the pH-responsive release of ICG from SF specifically in the tumor acidic environment, and its substantial activation with near-infrared (NIR) light at 808 nm significantly enhanced the PTT efficiency. In vitro and in vivo photothermal experiments have shown that these ICG-SF nanoparticles were capable of devastating tumor cells merely under light-induced hyperthermia. Together, these results have suggested that the biocompatible ICG-SF nanoparticles prepared by the SCF process resulted in high PTT efficiency and may have a great potential as a delivery system for sustained cancer therapy.

A novel controlled release formulation of the Pin1 inhibitor ATRA to improve liver cancer therapy by simultaneously blocking multiple cancer pathways.

Hepatocellular carcinoma (HCC) is the second leading cause of cancer deaths worldwide largely due to lack of effective targeted drugs to simultaneously block multiple cancer-driving pathways. The identification of all-trans retinoic acid (ATRA) as a potent Pin1 inhibitor provides a promising candidate for HCC targeted therapy because Pin1 is overexpressed in most HCC and activates numerous cancer-driving pathways. However, the efficacy of ATRA against solid tumors is limited due to its short half-life of 45min in humans. A slow-releasing ATRA formulation inhibits solid tumors such as HCC, but can be used only in animals. Here, we developed a one-step, cost-effective route to produce a novel biocompatible, biodegradable, and non-toxic controlled release formulation of ATRA for effective HCC therapy. We used supercritical carbon dioxide process to encapsulate ATRA in largely uniform poly L-lactic acid (PLLA) microparticles, with the efficiency of 91.4% and yield of 68.3%, and ~4-fold higher Cmax and AUC over the slow-releasing ATRA formulation. ATRA-PLLA microparticles had good biocompatibility, and significantly enhanced the inhibitory potency of ATRA on HCC cell growth, improving IC50 by over 3-fold. ATRA-PLLA microparticles exerted its efficacy likely through degrading Pin1 and inhibiting multiple Pin1-regulated cancer pathways and cell cycle progression. Indeed, Pin1 knock-down abolished ATRA inhibitory effects on HCC cells and ATRA-PLLA did not inhibit normal liver cells, as expected because ATRA selectively inhibits active Pin1 in cancer cells. Moreover ATRA-PLLA microparticles significantly enhanced the efficacy of ATRA against HCC tumor growth in mice through reducing Pin1, with a better potency than the slow-releasing ATRA formulation, consistent with its improved pharmacokinetic profiles. This study illustrates an effective platform to produce controlled release formulation of anti-cancer drugs, and ATRA-PLLA microparticles might be a promising targeted drug for HCC therapy as PLLA is biocompatible, biodegradable and nontoxic to humans.