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Pulmonary fibrosis is an irreparable and life-threatening disease with only limited therapeutic options. The recent outbreak of COVID-19 has caused a sharp rise in the incidence of pulmonary fibrosis owing to SARS-CoV-2 infection-mediated acute respiratory distress syndrome (ARDS). The considerable oxidative damage caused by locally infiltrated immune cells plays a crucial role in ARDS, suggesting the potential use of antioxidative therapeutics. Here, we report the therapeutic potential of nanoparticles derived from the endogenous antioxidant and anti-inflammatory bile acid, bilirubin (BRNPs), in treating pulmonary fibrosis in a bleomycin-induced mouse model of the disease. Our results demonstrate that BRNPs can effectively reduce clinical signs in mice, as shown by histological, disease index evaluations, and detection of biomarkers. Our findings suggest that BRNPs, with their potent antioxidant and anti-inflammatory effects, long blood circulation half-life, and preferential accumulation at the inflamed site, are potentially a viable clinical option for preventing Covid-19 infection-associated pulmonary fibrosis.

Despite the potential of photothermal therapy (PTT) for cancer treatments, PTT alone has limitations in treating metastatic tumors and preventing tumor recurrence, highlighting the need to combine PTT with immunotherapy. This study reports tumor microenvironment (TME)-targeting, near-infrared (NIR) dye derivative-based nanomedicine for effective combined PTT-immunotherapy. Amphiphilic NIR dye cyanine derivatives are used not only for constructing the nanoparticle mass, but also for creating a stable complex with CpG adjuvant; a peptide specific to fibronectin extra domain B (APTEDB) is also introduced as a TME-targeting ligand, yielding the TME-targeting nanomedicine, APTEDB-cyNP@CpG. APTEDB-cyNP@CpG shows cancer-targeting ability in EDB-overexpressing CT26 colon tumor-bearing mice. When combined with laser irradiation, it induces immunogenic cell death (ICD) and subsequently leads to significant increase in CD8+ T cell population in the tumor, resulting in greater antitumor therapeutic efficacy than does cyNP@CpG lacking the TME-targeting ligand. Moreover, the combination of APTEDB-cyNP@CpG-based PTT and an immune checkpoint blockade (ICB) antibody leads to remarkable antitumor efficacy against the laser-irradiated primary tumor as well as distant tumor through potentiation of systemic cancer cell-specific T cell immunity. Furthermore, the PTT-immunotherapy combination regimen is highly effective in inhibiting tumor recurrence and metastasis.

Transplanted islets suffer hypoxic stress, which leads to nonspecific inflammation. This is the major cause of islet graft failure during the early stage of intrahepatic islet transplantation. Although bilirubin has shown potent anti-oxidative and anti-inflammatory functions, its clinical applications have been limited due to its insolubility and short half-life. To overcome this problem, novel amphiphilic bilirubin nanoparticles are designed. Hydrophilic poly(ethylene glycol) (PEG) is conjugated to the hydrophobic bilirubin molecule. Then, the PEG-bilirubin conjugates form nanoparticles via self-assembly, i.e., so-called to BRNPs. BRNPs can protect islet cells not only from chemically induced oxidative stress by scavenging reactive oxygen species molecules, but also from activated macrophages by suppressing cytokine release. Importantly, in vivo experiments demonstrate that BRNP treatment can dramatically and significantly prolong islet graft survival compared to bilirubin treatment. In addition, immunohistochemical analysis shows BRNPs have potent anti-oxidative and anti-inflammatory capabilities. Collectively, novel BRNPs can be a new potent remedy for successful islet transplantation.

Hepatic ischemia-reperfusion injury (IRI) remains a major concern in liver transplantation and resection, despite continuing efforts to prevent it. Accumulating evidence suggests that bilirubin possesses antioxidant, anti-inflammatory and anti-apoptotic properties. However, despite obvious potential health benefits of bilirubin, its clinical applications are limited by its poor solubility. We recently developed bilirubin nanoparticles (BRNPs) consisting of polyethylene glycol (PEG)-conjugated bilirubin. Here, we sought to investigate whether BRNPs protect against IRI in the liver by preventing oxidative stress. BRNPs exerted potent antioxidant and anti-apoptotic activity in primary hepatocytes exposed to hydrogen peroxide, a precursor of reactive oxygen species (ROS). In a model of hepatic IRI in mice, BRNP preconditioning exerted profound protective effects against hepatocellular injury by reducing oxidative stress, pro-inflammatory cytokine production, and recruitment of neutrophils. They also preferentially accumulated in IRI-induced inflammatory lesions. Collectively, our findings indicate that BRNP preconditioning provides a simple and safe approach that can be easily monitored in the blood like endogenous bilirubin, and could be a promising strategy to protect against IRI in a clinical setting.

Although PEGylated liposomes (PEG-LS) have been intensively studied as drug-delivery vehicles, the rigidity and the hydrophilic PEG corona of liposomal membranes often limits cellular uptake, resulting in insufficient drug delivery to target cells. Thus, it is necessary to develop a new type of lipid-based self-assembled nanoparticles capable of enhanced cellular uptake, tissue penetration, and drug release than conventional PEGylated liposomes. Herein, we describe a simple modification of bicellar formulation in which the addition of a PEGylated phospholipid produced a dramatic physicochemical change in morphology, i.e., the disc-shaped bicelle became a uniformly distributed ultra-small (∼12 nm) spherical micelle. The transformed lipid-based nanoparticles, which we termed hyper-cell-permeable micelles (HCPMi), demonstrated not only prolonged stability in serum but also superior cellular and tumoral uptake compared to a conventional PEGylated liposomal system (PEG-LS). In addition, HCPMi showed rapid cellular uptake and subsequent cargo release into the cytoplasm of cancer cells. Cells treated with HCPMi loaded with docetaxel (DTX) had an IC50 value of 0.16 μM, compared with 0.78 μM with PEG-LS loaded with DTX, a nearly five-fold decrease in cell viability, indicating excellent efficiency in HCPMi uptake and release. In vivo tumor imaging analysis indicated that HCPMi penetrated deep into the tumor core and achieved greater uptake than PEG-LS. Results of HCPMi (DTX) treatment of allograft and xenograft mice in vivo showed high tumoral uptake and appreciable tumor retardation, with ∼70% tumor weight reduction in the SCC-7 allograft model. Taken together, these findings indicate that HCPMi could be developed further as a highly competent lipid-based drug-delivery system.

Although asthma, a chronic inflammatory airway disease, is relatively well-managed by inhaled corticosteroids, the side effects associated with the long-term use of these agents precipitate the need for alternative therapeutic options based on differing modes of action. Bilirubin, a potent endogenous antioxidant, and anti-inflammatory molecule have been shown to ameliorate asthmatic symptoms; however, its clinical translation has been limited owing to its water insolubility and associated potential toxicity. Here we report the first application of bilirubin-based nanoparticles (BRNPs) as a nanomedicine for the treatment of allergic lung inflammatory disease. BRNPs were prepared directly from self-assembly of PEGylated bilirubin in aqueous solution and had a hydrodynamic diameter of ∼100 nm. Because allergen-specific type 2 T-helper (Th2) cells play a key role in the pathogenesis and progression of allergic asthma, the effects of BRNPs on Th2 immune responses were investigated both in vivo and in vitro. BRNPs after intravenous injection (i.v.) showed much higher serum concentration and a longer circulation time of bilirubin than the intraperitoneal injection (i.p.) of BRNPs or unconjugated bilirubin (UCB). The anti-asthmatic effects of BRNPs were assessed in a mouse model of allergen-induced asthma. Compared with UCB, treatment with BRNPs suppressed the symptoms of experimental allergic asthma and dramatically ameliorated Th2-related allergic lung inflammation. Consistent with these results, BRNPs caused a reduction of Th2 cell populations and the expression of related cytokines by antibody-stimulated CD4+ T cells in vitro. Therefore, our results establish BRNPs as an important immunomodulatory agent that may be useful as a therapeutic for allergic lung inflammatory disease and other immune-mediated disorders.

Age-related macular degeneration and diabetic retinopathy are leading causes of blindness. Vascular endothelial growth factor (VEGF) is known to be the main factor that induces pathological angiogenesis in these diseases. In this study, we investigate the therapeutic potential and safety profiles of high-affinity peptides targeting VEGF which are identified using an 'aptide' technology. We show that two VEGF-binding aptides, APTVEGF1 and APTVEGF2, demonstrate high binding affinity and specificity to VEGF. Furthermore, they suppress VEGF-induced activation of VEGF receptor-2, in vitro angiogenesis, and in vivo pathological choroidal and retinal neovascularization. Despite potent anti-angiogenic effects, both VEGF-binding aptides do not induce any definite toxicity at the level of cellular viability, histological integrity, and gene expression. Our data show the therapeutic potential of VEGF-binding peptides for the treatment of choroidal and retinal neovascularization.

We have designed a dual-aptamer complex specific to both prostate-specific membrane antigens (PSMA) (+) and (-) prostate cancer cells. In the complex, an A10 RNA aptamer targeting PSMA (+) cells and a DUP-1 peptide aptamer specific to PSMA (-) cells were conjugated through streptavidin. Doxorubicin-loaded onto the stem region of the A10 aptamer was delivered not only to PSMA (+) cells but to PSMA (-) cells, and eventually induced apoptosis in both types of prostate cancer cells. Cell death was monitored by measuring guanine concentration in cells using differential pulse voltammetry (DPV), a simple and rapid electrochemical method, and was further confirmed by directly observing cell morphologies cultured on the transparent indium tin oxide (ITO) glass electrode and checking their viabilities using a trypan blue assay. To investigate the in vivo application of the dual-aptamer system, both A10 and DUP-1 aptamers were immobilized on the surface of thermally cross-linked superparamagnetic iron oxide nanoparticles (TCL-SPION). Selective cell uptakes and effective drug delivery action of these probes were verified by Prussian blue staining and trypan blue staining, respectively.

The work demonstrated the development of thermally cross-linked superparamagnetic nanomaterial which possessed polyethylene glycol moiety and covalently linked branched polyethylenimine (BPEI), and exhibited highly efficient magnetofection even under serum conditioned media. The study showed its high anti-biofouling, cell viability and serum stability and thus revealed a potential magnetic nanoparticle-mediated targeted gene delivery system. This superparamagnetic particle mediated rapid and efficient transfection in primary vascular endothelial cells (HUVEC) successfully inhibits expression of PAI-1 which is responsible for various vascular dysfunctions such as vascular inflammation and atherosclerosis and thereby provides a potential strategy to transfect highly sensitive HUVEC. The sequential steps for the enhanced magnetofection had been studied by monitoring cellular uptake with the aid of confocal microscopy.