An Albumin-Based Therapeutic Nanosystem for Photosensitizer/Protein Co-Delivery to Realize Synergistic Cancer Therapy

Oxygen-dependent photodynamic therapy (PDT) is hindered by the limited availability of endogenous oxygen in solid tumors and low tumor accumulation of photosensitizers. Herein, we developed a biocompatible cancer-targeted therapeutic nanosystem based on cRGD conjugated bovine serum albumin (CBSA) co-loaded with a photosensitizer (chlorin e6, Ce6) and a therapeutic protein (cytochrome c, Cytc) for synergistic photodynamic and protein therapy. The nanosystem (Ce6/Cytc@CBSA) can target αVβ3 integrin overexpressed cancer cells to improve tumor accumulation due to incorporation of cRGD. In the intracellular environment, Ce6 is released to produce toxic singlet oxygen upon near-infrared irradiation. At the same time, the therapeutic protein, Cytc, can induce programmed cell death by activating the downstream caspase pathway. Most importantly, Cytc with the catalase-like activity accelerates O2 generation by decomposing excess H2O2 in cancer cells, thereby relieving the PDT-induced hypoxia to enhance therapeutic efficacy. Both in vitro and in vivo studies reveal the significantly improved antitumor effects of the combined photodynamic/protein therapy, indicating that Ce6/Cytc@CBSA shows great potential in synergetic cancer treatments.

Alkylaminomaleimide fluorophores: synthesis via air oxidation and emission modulation by twisted intramolecular charge transfer

A novel strategy to synthesize 3-alkylaminomaleimide fluorophores via air oxidation is developed, and the structural features for the designed TICT fluorophores with bright emission are established.

Biotinylated and fluorophore-incorporated polymeric mixed micelles for tumor cell-specific turn-on fluorescence imaging of Al3

Excessive amounts of Al3+ in the human body can cause adverse effects on immune function and induce several neurodegenerative disorders. So far, most of the reported fluorescent probes for Al3+ present some common drawbacks, such as low sensitivity and poor water solubility. In addition, a number of traditional fluorescent probes failed to image Al3+ in tumor cells due to the lack of tumor cell targeting capacity and cell penetrating abilities. To overcome these shortcomings, we constructed tumor-targeting fluorescent mixed nano-micelles (mPEG-Dye-Biotin) with an average particle size of 21 nm from an amphiphilic polymer containing a Schiff-base fluorescent unit (mPEG-Dye) and another amphiphilic polymer containing a tumor cell recognition ligand (DSPE-PEG-Biotin), through the co-self-assembly of both amphiphilic polymers in water using the film rehydration method. The as-prepared nanoprobe showed a highly sensitive and selective turn-on fluorescence response to Al3+ in aqueous solution with a low detection limit. MTT assay revealed the negligible cytotoxicity of the mPEG-Dye-Biotin nanoprobe to both HeLa cells and COS-7 cells, indicating the safety of mPEG-Dye-Biotin for biological applications. More importantly, the biotinylated nanoprobe showed better ability to enter biotin receptor-positive HeLa cells than that of the non-biotinylated micelle mPEG-Dye, which made it more suitable for imaging Al3+ in biotin receptor-positive tumor cells. This work provides a simple and general strategy to design a highly sensitive and tumor cell-specific metal ion nanoprobe, which can not only be applied in Al3+ imaging, but can also be extended to other ions or biomolecules by changing the incorporated fluorescent unit in the amphiphilic polymer.

Aptamer/Peptide-Functionalized Genome-Editing System for Effective Immune Restoration through Reversal of PD-L1-Mediated Cancer Immunosuppression

Effective reversal of tumor immunosuppression is of critical importance in cancer therapy. A multifunctional delivery vector that can effectively deliver CRISPR-Cas9 plasmid for β-catenin knockout to reverse tumor immunosuppression is constructed. The multi-functionalized delivery vector is decorated with aptamer-conjugated hyaluronic acid and peptide-conjugated hyaluronic acid to combine the tumor cell/nuclear targeting function of AS1411 with the cell penetrating/nuclear translocation function of TAT-NLS. Due to the significantly enhanced plasmid enrichment in malignant cell nuclei, the genome editing system can induce effective β-catenin knockout and suppress Wnt/β-catenin pathway, resulting in notably downregulated proteins involved in tumor progression and immunosuppression. Programmed death-ligand 1 (PD-L1) downregulation in edited tumor cells not only releases the PD-1/PD-L1 brake to improve the cancer killing capability of CD8⁺ T cells, but also enhances antitumor immune responses of immune cells. This provides a facile strategy to reverse tumor immunosuppression and to restore immunosurveillance and activate anti-tumor immunity.

[Effect of non-diabetic postoperative hyperglycemia on complications after pancreaticoduodenectomy]

Objective: To examine the association of hyperglycemia and postoperative complications in non-diabetic patients underwent pancreaticoduodenectomy(PD). Methods: The clinical data of 209 non-diabetic patients who underwent PD from January 2012 to June 2018 at Department of Pancreatic and Biliary Surgery, the First Affiliated Hospital of Harbin Medical University and met the inclusion criteria were retrospectively analyzed. According to the diagnostic criteria of postoperative hyperglycemia, the patients were divided into postoperative hyperglycemia group (167 cases, 79.9%) and control group(42 cases, 20.1%). The propensity score matching(PSM) method was used to eliminate the difference between groups(caliper value=0.02; 38 cases in control group including 30 males and 8 females with age of 59.0 years;38 cases in postoperative hyperglycemia group including 32 males and 6 females with age of 61.0 years;37 cases of pancreatic head carcinoma,30 cases of periampullary carcinoma and 9 cases of benign diseases). A comparative analysis was applied for preoperative data, surgical related indicators and postoperative complication rates.The receiver operating characteristic(ROC) curve was used to calculate the area under the curve(AUC) of blood glucose values on postoperative day 1,3 and 5(POD1, POD3, POD5), to determine the high-risk blood glucose cutoff value of complications and to evaluate its sensitivity and specificity for the prediction of postoperative complications. Results: Univariate analysis showed that the differences in gender, body mass index, preoperative blood glucose, and serum urea nitrogen levels were statistically significant before PSM.There was no significant difference in the preoperative data between the two groups after PSM. Compared with the control group, the incidence of postoperative pancreatic fistula (31.6% vs. 5.3%), abdominal infection(29.0% vs. 7.9%) and Clavien-Dindo Ⅲ-Ⅴ complications(31.6% vs.7.9%) were statistically different(χ(2)=7.092,P=0.008; χ(2)=4.290,P=0.038; χ(2)=5.316,P=0.021), respectively. According to the AUC on POD3,the blood glucose value ≥8.860 mmol/L was an independent risk factor for pancreatic fistula with sensitivity of 58.3% and specificity of 76.9%,the blood glucose value ≥9.130 mmol/L was an independent risk factor for abdominal infection with sensitivity of 54.5% and specificity of 81.5% and the blood glucose value ≥7.685 mmol/L was independent risk factor of Clavien-Dindo Ⅲ-Ⅴ complications with sensitivity of 75.0% and specificity of 57.7%. Conclusions: Postoperative hyperglycemia in non-diabetic patients is associated with postoperative pancreatic fistula, abdominal infection, and Clavien-Dindo Ⅲ-Ⅴ complications.According to the early postoperative blood glucose value,the occurrence of postoperative pancreatic fistula, abdominal infection and Clavien-Dindo Ⅲ- Ⅴ complications can be effectively predicted.

Targeting Delivery of Oligodeoxynucleotides to Macrophages by Mannosylated Cationic Albumin for Immune Stimulation in Cancer Treatment

To efficiently deliver CpG oligodeoxynucleotides (ODNs) to macrophages for the reversal of cancer-induced immunosuppression, nanoparticles ODN@MCBSA with mannosylated cationic albumin (MCBSA) as a macrophage targeting vector were constructed. Compared with ODN@CBSA with cationic albumin (CBSA) as a vector, ODN@MCBSA exhibited significantly improved cellular uptake mediated by mannose moieties, resulting in significantly enhanced secretion of proflammatory cytokines including IL-12, IL-6, TNF-α, and iNOS. The modulation of macrophages toward the favorable M1 phenotype was confirmed by the upregulated CD80 expression after being treated by ODN delivery systems. In addition to immune cells, the effects of the ODN delivery system on cancerous HeLa cells were also investigated. The results showed that ODN@MCBSA did not affect the overall tumor cell viability. However, enhanced NF-κB, p-Akt, PIK3R3, Fas, and FasL, as well as upregulated caspases were observed in tumor cells, implying the pleiotropic effects on tumor cells. Our study provides a more in-depth understanding on the immunotherapeutic effects of CpG ODNs and highlights the importance of macrophage targeting delivery to minimize the effects on tumor cells. These results indicate that MCBSA could serve as a promising delivery vector of CpG ODNs to macrophages for cancer immunotherapy.

Aptamer-functionalized albumin-based nanoparticles for targeted drug delivery

Proteins have been extensively explored as versatile nanocarriers for drug delivery due to their complete biocompatibility, ease of surface modification, and lack of toxicity and immunogenicity. In this study, a facile strategy was used to construct aptamer-functionalized albumin-based nanoparticles for effective drug delivery and targeted cancer therapy. A hydrophobic drug, doxorubicin (DOX) was employed to trigger the self-assembly of bovine serum albumin (BSA) to from stable nanoparticles via hydrophobic interaction, and then a tumor targeting aptamer AS1411 was incorporated to the surface of DOX loaded BSA. Due to the specific recognition between AS1411 and its receptor over-expressed on tumor cells, the aptamer-modified nanoparticles show higher cellular uptake and stronger cell inhibitory efficacy against cancerous MCF-7 cells as compared with the nanoparticles without aptamer modification. In addition, DOX loaded aptamer-functionalized nanoparticles can induce more significant down-regulation of Bcl-2 and PCNA as well as up-regulation of pRB, PARP and Bax in MCF-7 cells compared with unmodified nanoparticles, indicating the aptamer modification can induce cell apoptosis more effectively. Besides, aptamer-modified nanoparticles exhibit a significantly improved capability in up-regulating p16, p21 and E-cadherin, and down-regulating EpCAM, vimentin, Snail, MMP-9, CD44 and CD133, implying the favorable effects of drug delivery on the prevention of tumor progression and metastasis.

A Dual Macrophage Targeting Nanovector for Delivery of Oligodeoxynucleotides To Overcome Cancer-Associated Immunosuppression

To overcome cancer-associated immunosuppression, we prepared a dual-targeting vector to deliver CpG oligodeoxynucleotides (ODN) to macrophages. The dual-targeting system composed of mannosylated carboxymethyl chitosan (MCMC)/hyaluronan (HA) for macrophage targeting and protamine sulfate for ODN complexation was prepared by self-assembly. The effects of ODN delivery on immune cells was studied in J774A.1 cells. Due to the enhanced delivery efficiency, the dual-targeting delivery system exhibits a higher immune stimulatory activity compared with the monotargeting delivery system containing either MCMC or HA, resulting in a dramatically enhanced secretion of proinflammatory cytokines and a successful shift to activated macrophages (M1). Besides macrophages, the influence of the delivery system on tumor cells (MCF-7) was also investigated. In MCF-7 cells, the increased expressions of nuclear transcription factor-κB (NF-κB), PIK3R3, and phosphorylated protein kinase B (p-Akt) caused by activated NF-κB and phosphoinositide 3-kinase/Akt signalings were observed. Nevertheless, upregulated Fas as well as Fas ligand (FasL) may induce Fas/FasL-mediated apoptosis, which results in the increased expressions of caspases in tumor cells.