Polyamidoamine dendrimer-mediated hydrogel for solubility enhancement and anti-cancer drug delivery

The application of hydrogels for anti-cancer drug delivery has garnered considerable interest in the medical field. Current cancer treatment approaches, such as chemotherapy and radiation therapy, often induce severe side effects, causing significant distress and substantial health complications to patients. Hydrogels present an appealing solution as they can be precisely injected into specific sites within the body, facilitating the sustainable release of encapsulated drugs. This localized treatment approach holds great potential for reducing toxicity levels and improving drug delivery efficacy. In this study we developed a hydrogel delivery system containing polyamidoamine (PAMAM) dendrimer and polyethylene glycol (PEG) for solubility enhancement and sustained delivery of hydrophobic anti-cancer drugs. The three selected model drugs, e.g. silibinin, camptothecin, and methotrexate, possess limited aqueous solubility and thus face restricted application. In the presence of vinyl sulfone functionalized PAMAM dendrimer at 45 mg/mL concentration, drug solubility is increased by 37-fold, 4-fold, and 10-fold for silibinin, camptothecin, and methotrexate, respectively. By further crosslinking of the functionalized PAMAM dendrimer and thiolated PEG, we successfully developed a fast-crosslinking hydrogel capable of encapsulating a significant payload of solubilized cancer drugs for sustained release. In water, the drug encapsulated hydrogels release 30%-80% of their loads in 1-4 days. MTT assays of J82 and MCF7 cells with various doses of drug encapsulated hydrogels reveal that cytotoxicity is observed for all three drugs on both J82 and MCF7 cell lines after 48 h. Notably, camptothecin exhibits higher cytotoxicity to both cell lines than silibinin and methotrexate, achieving up to 95% cell death at experimental conditions, despite its lower solubility. Our experiments provide evidence that the PAMAM dendrimer-mediated hydrogel system significantly improves the solubility of hydrophobic drugs and facilitates their sustained release. These findings position the system as a promising platform for controlled delivery of hydrophobic drugs for intratumoral cancer treatment.

Primary endometrial T-cell lymphoma. A case report

Primary lymphomas of the female genital tract are rare. Most involve the cervix rather than the uterine corpus. All of those previously reported have been B-cell lymphomas, with the exception of 1 case report of an endometrial T-cell lymphoma in a Japanese woman. We report the case of a white woman from the United States with a diffuse large cell lymphoma of the endometrium, characterized as a peripheral T-cell type on the basis of immunophenotypic and molecular probe studies. Staging evaluation revealed tumor limited to the endometrium (stage IE). The patient underwent a total abdominal hysterectomy, bilateral salpingo-oophorectomy, and lymph node dissection and received 6 cycles of combination chemotherapy, after which she remained free of disease at last follow-up of 36 months. Unusual features of this lymphoma case are discussed, with emphasis on differential diagnosis and speculation on histogenesis. This case illustrates that, while most peripheral T-cell lymphomas are widely disseminated at presentation, those limited to a single extranodal site may have a favorable outcome akin to that associated with high-grade extranodal B-cell lymphomas of early stage.

Laboratory recognition of a rare hemoglobinopathy: hemoglobins SS and SG(Philadelphia) associated with alpha-thalassemia-2

This article describes the laboratory investigation of an unusual hemoglobinopathy involving hemoglobin (Hb) S, HbSG(Philadelphia), and alpha-thalassemia-2 in a patient whose phenotype was HbSC by alkaline electrophoresis. Findings of a mean corpuscular volume of 62 fL and microcytes on the blood smear were inconsistent with HbSC disease. The patient's clinical course over several years had been mildly symptomatic. Testing in our hospital laboratory using isoelectric focusing and cation-exchange high-performance liquid chromatography to separate hemoglobins showed an unknown variant. Additional studies, including globin chain electrophoresis, reverse-phase high-performance liquid chromatography, and polymerase chain reaction-based DNA analysis were performed at reference laboratories, which reported the following findings: HbG(Philadelphia) associated with alpha-thalassemia-2, HbS and HbG(Philadelphia), and the alpha-globin deletions defining the -alpha3.7/-alpha3.7 genotype. The hemoglobin molecular defects, alpha-thalassemia-2, and the pattern of inheritance are discussed.

Primary hepatic B-cell lymphoma of mucosa-associated lymphoid tissue

Mucosa-associated lymphoid tissue (MALT) lymphomas are low-grade B-cell lymphomas that occur in a variety of extranodal sites but rarely as a primary hepatic lymphoma. We describe the histological findings, immunophenotype, and immunohistochemistry of one such lymphoma found incidentally in a 69-year-old woman. The lymphoid infiltrate invaded the liver in a serpiginous configuration with entrapment of nodules of normal liver. Reactive follicles were surrounded by intermediate-sized lymphoid cells with slightly irregular nuclei and pale cytoplasm. Only a few scattered lymphoepithelial lesions were identified since most of the bile ducts were destroyed. The immunophenotype determined by flow cytometry identified the lymphoid cells as being CD19, CD20 positive and exhibiting lambda light chain restriction. CD5, CD10, and CD23 were negative. Immunohistochemistry showed the neoplastic cells to be positive for CD20 (L-26) and bcl-2. The reactive follicles were negative for bcl-2. CD3 showed only a few scattered T cells. Cyclin D1 did not stain the neoplastic cells. Cytokeratin (AE1/AE3) highlighted the lymphoepithelial lesions and residual bile ducts. MALT lymphomas need to be recognized and distinguished from other B-cell lymphomas, particularly mantle cell lymphomas, because of the difference in behavior and treatment.

Paramagnetic organometallic molecules. XIV. Ion-pair and steric effects in dissociative electron transfer reactions of metal cluster carbonyl radical anions

An investigation of electron attachment reactions of cluster metal carbonyls is presented. In general, alkyl and organometallic halides react rapidly with metal carbonyl cluster radical anions at ambient temperatures to give the neutral cluster molecule. Halide ion and alkyl or organometallic radicals are also produced, which indicate that these are dissociative electron attachment reactions analogous to those of organic radical anions. The rate of dissociative electron attachment in reactions of PhCCo3(CO)9- was found to depend on the R-X bond energy, the size of the alkyl group and the nature of the counter-ion. In particular, (Ph3P)2N+ retarded some electron transfer reactions to the extent that the bimolecular decay of PhCCo3(CO)9- effectively competed with the electron transfer process in determining the reaction path.

13C coupling in the E.S.R. spectrum of the pyrene anion in tetrahydrofuran

Examination of the e.s.r, spectrum of pyrene anion in tetrahydrofuran under conditions of high resolution has yielded the 13C hyperfine coupling parameters for five of the six carbon positions. The parameters agree well with those calculated by molecular orbital methods. No evidence of ion pair formation was found under the conditions used in these experiments.