Severe acute respiratory syndrome (SARS) coronavirus has been known to damage multiple organs; however, little is known about its impact on the reproductive system. In the present study, we analyzed the pathological changes of testes from six patients who died of SARS. Results suggested that SARS caused orchitis. All SARS testes displayed widespread germ cell destruction, few or no spermatozoon in the seminiferous tubule, thickened basement membrane, and leukocyte infiltration. The numbers of CD3þ T lymphocytes and CD68þ macrophages increased significantly in the interstitial tissue compared with the control group (P , 0.05). SARS viral genomic sequences were not detected in the testes by in situ hybridization. Immunohistochemistry demonstrated abundant IgG precipitation in the seminiferous epithelium of SARS testes, indicating possible immune response as the cause for the damage. Our findings indicated that orchitis is a complication of SARS. It further suggests that the reproductive functions should be followed and evaluated in recovered male SARS patients.immunohistochemistry, in situ hybridization, orchitis, SARS, spermatogenesis, testis

Hypoxia, a typical feature of solid tumors, remarkably restricts the efficiency of photodynamic therapy (PDT). Here, a carbon nitride (C3N4)-based multifunctional nanocomposite (PCCN) for light-driven water splitting was used to solve this problem. Carbon dots were first doped with C3N4 to enhance its red region absorption because red light could be used to trigger the in vivo water splitting process. Then, a polymer containing a protoporphyrin photosensitizer, a polyethylene glycol segment, and a targeting Arg-Gly-Asp motif was synthesized and introduced to carbon-dot-doped C3N4 nanoparticles. In vitro study showed that PCCN, thus obtained, could increase the intracellular O2 concentration and improve the reactive oxygen species generation in both hypoxic and normoxic environments upon light irradiation. Cell viability assay demonstrated that PCCN fully reversed the hypoxia-triggered PDT resistance, presenting a satisfactory growth inhibition of cancer cells in an O2 concentration of 1%. In vivo experiments also indicated that PCCN had superior ability to overcome tumor hypoxia. The use of water splitting materials exhibited great potential to improve the intratumoral oxygen level and ultimately reverse the hypoxia-triggered PDT resistance and tumor metastasis.

Conventional oxygen‐dependent photodynamic therapy (PDT) has faced severe challenges because of the non‐specificity of most available photosensitizers (PSs) and the hypoxic nature of tumor tissues. Here, an O2 self‐sufficient cell‐like biomimetic nanoplatform (CAT‐PS‐ZIF@Mem) consisting of the cancer cell membrane (Mem) and a cytoskeleton‐like porous zeolitic imidazolate framework (ZIF‐8) with the embedded catalase (CAT) protein molecules and Al(III) phthalocyanine chloride tetrasulfonic acid (AlPcS4, defined as PS) is developed. Because of the immunological response and homologous targeting abilities of the cancer cell membrane, CAT‐PS‐ZIF@Mem is selectively accumulated at the tumor site and taken up effectively by tumor cells after intravenous injection. After the intracellular H2O2 penetration into the framework, it is catalyzed by CAT to produce O2 at the hypoxic tumor site, facilitating the generation of toxic 1O2 for highly effective PDT in vivo under near‐infrared irradiation. By integrating the immune escape, cell homologous recognition, and O2 self‐sufficiency, this cell‐like biomimetic nanoplatform demonstrates highly specific and efficient PDT against hypoxic tumor cells with much reduced side‐effect on normal tissues.

Discovering advanced materials for regulating cell death is of great importance in the development of anticancer therapy. Herein, by harnessing the recently discovered oxidative stress regulation ability of p53 and the Fenton reaction inducing capability of metal-organic network (MON), MON encapsulated with p53 plasmid (MON-p53) was designed to eradicate cancer cells via ferroptosis/apoptosis hybrid pathway. After confirming the detailed mechanism of MON-p53 in evoking ferroptosis, we further discovered that MON-p53 mediated a "bystander effect" to further sensitize cancer cells toward the MON-p53 induced ferroptosis. A 75-day anticancer experiment indicated that MON-p53 treatment not only suppressed the tumor growth but also prolonged the life-span of tumor bearing mice. Owing to its ability to promote intracellular oxidative stress, MON-p53 decreased the blood metastasis, lung metastasis, and liver metastasis. As a consequence, discovering methods to induce cell ferroptosis would provide a new insight in designing anticancer materials.

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In this paper, a self‐delivery system PpIX‐PEG‐(KLAKLAK)2 (designated as PPK) is fabricated to realize mitochondria‐targeted photodynamic tumor therapy. It is found that the PPK self‐delivery system exhibited high drug loading efficacy as well as novel capacity in generation of intracellular reactive oxygen species (ROS). This study also indicated that the photochemical internalization effect of the photosensitizer protoporphyrin IX (PpIX) under a short time light irradiation improved the cellular internalization of PPK. On the contrary, PPK could target to the subcellular organelle mitochondria due to the presence of proapoptosis (KLAKLAK)2 peptide. Importantly, the in situ generation of ROS in mitochondria enhanced the photodynamic therapy efficacy under another long time irradiation, leading to significant cell death with decreased mitochondrial membrane potential. Besides, relative high tumor accumulation, minimal systemic cytotoxicity and efficacious long‐term tumor inhibition in vivo are also confirmed by using a murine model. All these results demonstrated the self‐delivery system PPK with a dual‐stage light irradiation strategy is a promising nanoplatform for tumor treatment.

In this study, we developed a general method to decorate plasmonic gold nanorods (GNRs) with a CD44-targeting functional polymer, containing a hyaluronic acid (HA)-targeting moiety and a small molecule Glut1 inhibitor of diclofenac (DC), to obtain GNR/HA-DC. This nanosystem exhibited the superiority of selectively sensitizing tumor cells for photothermal therapy (PTT) by inhibiting anaerobic glycolysis. Upon specifically targeting CD44, sequentially time-dependent DC release could be achieved by the trigger of hyaluronidase (HAase), which abundantly existed in tumor tissues. The released DC depleted the Glut1 level in tumor cells and induced a cascade effect on cellular metabolism by inhibiting glucose uptake, blocking glycolysis, decreasing ATP levels, hampering heat shock protein (HSP) expression, and ultimately leaving malignant cells out from the protection of HSPs to stress (e.g., heat), and then tumor cells were more easy to kill. Owing to the sensitization effect of GNR/HA-DC, CD44 overexpressed tumor cells could be significantly damaged by PTT with an enhanced therapeutic efficiency in vitro and in vivo.

Photodynamic therapy faces the barrier of choosing the appropriate irradiation region and time. In this paper, a matrix metalloproteinase-2 (MMP-2) responsive ratiometric biosensor was designed and synthesized for aggregation-induced emission (AIE)-guided precise photodynamic therapy. It was found that the biosensor presented the MMP-2 responsive AIE behavior. Most importantly, it could accurately differentiate the tumor cells from the healthy cells by the fluorescence ratio between freed tetraphenylethylene and protoporphyrin IX (PpIX, internal reference). In vivo study demonstrated that the biosensor could preferentially accumulate in the tumor tissue with a relative long blood retention time. Note that the intrinsic fluorescence of PpIX and MMP-2-triggered AIE fluorescence provided a real-time feedback which guided precise photodynamic therapy in vivo efficiently. This strategy demonstrated here opens a window in the precise medicine, especially for phototherapy.