Chemotherapy:

pH-Responsive Nano-Self-Assemblies of the Anticancer Drug 2-Hydroxyoleic Acid

pH-responsive lipid nanocarriers have the potential to selectively target the acidic extracellular pH environment of cancer tissues and may further improve the efficacy of chemotherapeutics by minimizing their toxic side-effects. Here, we present the design and characterization of pH-sensitive nano-self-assemblies of the poorly water-soluble anticancer drug 2-hydroxyoleic acid (2OHOA) with glycerol monooleate (GMO). pH-triggered nanostructural transformations from 2OHOA/GMO nanoparticles with an internal inverse hexagonal structure (hexosomes) at pH around 2.0-3.0, via nanocarriers with an internal inverse bicontinuous cubic structure (cubosomes) at pH 2.0-4.5, to vesicles at pH 4.5-7.4 were observed with synchrotron small-angle X-ray scattering, and cryogenic transmission electron microscopy. ζ-potential measurements highlight that the pH-driven deprotonation of the carboxylic group of 2OHOA, and the resulting charge-repulsions at the lipid-water interface account for these nanostructural alterations. The study provides detailed insight into the pH-dependent self-assembly of 2OHOA with GMO in excess buffer at physiologically relevant pH values, and discusses the effects of pH alterations on modulating their nanostructure. The results may guide the further development of pH-responsive anticancer nanocarriers for the targeted delivery of chemotherapeutics to the local microenvironment of tumor cells.

A rare cause of hearing loss in a child

Neurofibromatosis type 2 is a rare genetic disease affecting the central and peripheral nervous systems and characterized by schwannomas, meningiomas, and ependymomas. Prompt symptom recognition, diagnosis, and proper referrals can increase treatment effectiveness and decrease the mortality risk of this life-threatening disease.

Neurofibromatosis type 2 vestibular schwannoma treatment: a review of the literature, trends, and outcomes

OBJECTIVE

Review the useful hearing preservation and tumor control outcomes of microsurgery (MS), stereotactic radiation (SR), conservative management (CM), and chemotherapy (ChT) for Neurofibromatosis type 2 vestibular schwannomas.

DATA SOURCES

Ovid MEDLINE was used to conduct a thorough search of English-language publications dating from 1948 to February 2013.

STUDY SELECTION

Patients must have had useful hearing at diagnosis and treated with one of the 4 treatments as their primary therapy. All sporadic vestibular schwannoma cases were excluded.

DATA EXTRACTION

A total of 19 articles were reviewed. Hearing preservation was defined as unchanged or improved useful hearing. Tumor control was defined as no change in size or tumor regression for SR, CM, and ChT-treated cases, and as no recurrence for MS treated cases.

CONCLUSION

Microsurgery seems to have the worse overall results, while SR has very good tumor control with poor useful hearing preservation. If a patient qualifies for CM, he is likely to show the most satisfactory results with the least treatment available. A close follow-up on ChT clinical trials and possible side-effects is warranted as preliminary short-term results are quite favorable. Additional long-term studies are required for a better understanding of this disease.

Non surgical treatment of vestibular schwannoma

INTRODUCTION AND OBJECTIVES

To evaluate the results of local control and complications in the treatment of vestibular schwannoma treated with radiation.

METHODS

A retrospective study of 194 patients diagnosed with vestibular schwannoma, treated consecutively with radiation (either stereotactic radiosurgery or fractionated radiotherapy) from 1997 to 2012. We analyze the local control of tumors, as well as secondary complications to treatment with radiation.

RESULTS

A total of 132 (68%) tumors 68% are grade I-II tumors of the Koos classification, 40 (19%) are grade III, and 22 (13%) are grade IV. The tumors associated with neurofibromatosis (NF2), are 3.6% (6 tumors in 4 patients). The tumor control for the overall serie is 97% at 5 years, with a median follow-up of 80.4 months. For large tumors the local control is 91% at 5 years. Free survival of chronic complications is 89% at 5 years. Additionally, 50 tumors were subjected to regular follow-up with MRI without treatment, and 28 (58%) did not experienced tumor growth.

CONCLUSIONS

Radiation and follow up with MRI, are an alternative to surgery in the treatment of vestibular schwannoma, with a low level of complications inside of multidisciplinary approach.