Solid-State Formation of a Potential Melphalan Delivery Nanosystem Based on β-Cyclodextrin and Silver Nanoparticles

Melphalan (Mel) is an antineoplastic widely used in cancer and other diseases. Its low solubility, rapid hydrolysis, and non-specificity limit its therapeutic performance. To overcome these disadvantages, Mel was included in β-cyclodextrin (βCD), which is a macromolecule that increases its aqueous solubility and stability, among other properties. Additionally, the βCD-Mel complex has been used as a substrate to deposit silver nanoparticles (AgNPs) through magnetron sputtering, forming the βCD-Mel-AgNPs crystalline system. Different techniques showed that the complex (stoichiometric ratio 1:1) has a loading capacity of 27%, an association constant of 625 M^-1, and a degree of solubilization of 0.034. Added to this, Mel is partially included, exposing the NH₂ and COOH groups that stabilize AgNPs in the solid state, with an average size of 15 ± 3 nm. Its dissolution results in a colloidal solution of AgNPs covered by multiple layers of the βCD-Mel complex, with a hydrodynamic diameter of 116 nm, a PDI of 0.4, and a surface charge of 19 mV. The in vitro permeability assays show that the effective permeability of Mel increased using βCD and AgNPs. This novel nanosystem based on βCD and AgNPs is a promising candidate as a Mel nanocarrier for cancer therapy.

Prophylaxis and Treatment of Pneumocystis jiroveci Pneumonia in Lymphoma Patients Subjected to Rituximab-Contained Therapy: A Systemic Review and Meta-Analysis

Pneumocystis jiroveci pneumonia (PCP) is frequently reported in lymphoma patients treated with rituximab-contained regimens. There is a trend toward a difference in PCP risk between bi- and tri-weekly regimens. The aims of this systemic review and meta-analysis were to estimate the risk for PCP in these patients, compare the impact of different regimens on the risk, and evaluate the efficacy of prophylaxis. The cohort studies with incept up to January 2014 were retrieved from the Cochrane Library, Medline, Embase, and Web of Science databases. Studies that compared the incidence of PCP in patients with and without rituximab treatment were conducted. Studies that reported the results of prophylaxis were concentrated to evaluate the efficacy of prophylaxis. Fixed effect Mantel-Haenszel model was chosen as the main analysis method. Funnel plots were examined to estimate the potential selection bias. Egger's test and Begg's test were used for the determination of possible small study bias. Eleven cohort studies that met the inclusion criteria were finally included. Results indicated that rituximab was associated with a significantly increased risk for PCP (28/942 vs 5/977; risk ratio: 3.65; 95% confidence interval 1.65 to 8.07; P=0.001), and no heterogeneity existed between different studies (I2=0%). Little significant difference in PCP risk was found between bi-weekly and tri-weekly regimens (risk ratio: 3.11; 95% confidence interval 0.92 to 10.52, P=0.068). PCP risk was inversely associated with prophylaxis in patients treated with rituximab (0/222 vs 26/986; risk ratio: 0.28; 95% confidence interval 0.09 to 0.94; P=0.039). In conclusion, PCP risk was increased significantly in lymphoma patients subjected to rituximab-contained chemotherapies. Difference in PCP risk between bi-weekly and tri-weekly regimens was not significant. Additionally, prophylaxis was dramatically effective in preventing PCP in rituximab-received lymphoma patients, suggesting that rituximab should be recommended for these patients.

Interstitial pneumonia after autologous hematopoietic stem cell transplantation in B-cell non-hodgkin lymphoma

INTRODUCTION

During the past decade, interstitial pneumonia (IP) is one of the newly recognized adverse events regarding rituximab therapy. However, disease characteristics of IP after autologous hematopoietic stem cell transplantation (ASCT) have not been well-described since the introduction of rituximab.

PATIENTS AND METHODS

We retrospectively analyzed 103 patients with B-cell non-Hodgkin lymphoma undergoing ASCT. A propensity scoring system was applied in our analysis to eliminate potential confounding factors of covariates.

RESULTS

The total number of patients who developed IP was nine. Five patients developed IP among 57 patients previously treated with rituximab, and four patients developed IP among 46 who were rituximab-naïve. Cumulative incidence of IP was 7.8% at 1 year. Among the patients using rituximab, one patient had IP during the peri-engraftment period (cytomegalovirus infection), three patients had IP between 3 and 12 months (Pneumocystis pneumonia [PCP, n = 1] and unknown cause [n = 2]), and the other one patient had IP 3.3 years after ASCT (unknown cause). Four patients in the rituximab-naïve group developed IP between 3 and 12 months (PCP [n = 1] and unknown cause [n = 3]). All nine patients had symptomatic episodes before IP, three of which died of IP or secondary infections. Patients receiving a total body irradiation conditioning regimen had a higher risk of IP (odds ratio = 3.6, P < .001), whereas the incidence was not affected by rituximab usage (P = .85, Log-rank test).

CONCLUSION

This study shows that the rituximab usage was not identified as a risk factor of IP and that total body irradiation was the only independent risk factor for IP. Close monitoring is encouraged when symptomatic unexplained episodes are identified during follow-up examinations after ASCT.