Repeated dose 28-day oral toxicity study of DEAE-Dextran in mice: An advancement in safety chemotherapeutics.

Cancer has emerged as a global threat with challenges for safe chemotherapeutics. Most of the currently available anti-cancer drugs exhibit significant toxicity. Amongst novel agents, interferons have exhibited anti-proliferative and cytoprotective roles. However, due to stability drawbacks of interferons, we have identified an interferon inducer DEAE-Dextran, which resolves the stability issues. Based on the previous history of toxicity pertaining to the current chemotherapeutic agents, it is equally essential to determine the safety of DEAE-Dextran. In the present study, repeated dose 28 day oral toxicity of DEAE-Dextran has been evaluated in accordance to OECD-407. We found absence of any CNS behavioral changes related to self-mutilation, walking backwards, aggressiveness on handling or tonic-clonic seizures during the 28 day study. Neither the motor activity nor grip strength was altered during the treatment duration with DEAE-Dextran implying absence of any effect on the skeletal muscles. Interestingly, we also found that treatment with DEAE-Dextran did not present any significant cardiac, hepatic, renal, gastrointestinal, lymphatic or reproductive system toxicity or alteration in the body's normal physiology based upon the various organ function tests. Henceforth, it may be concluded that DEAE-Dextran is a safe anti-cancer agent devoid of any sub-acute toxicity.

2-diethylaminoethyl-dextran methyl methacrylate copolymer nonviral vector: still a long way toward the safety of aerosol gene therapy.

Revealing the lung tumor genome has directed the current treatment strategies toward targeted therapy. First line treatments targeting the genome of lung tumor cells have been approved and are on the market. However, they are limited by the small number of patients with the current investigated genetic mutations. Novel treatment administration modalities have been also investigated in an effort to increase the local drug deposition and disease control. In the current study, we investigated the safety of the new nonviral vector 2-diethylaminoethyl-dextran methyl methacrylate copolymer (DDMC; Ryujyu Science), which belongs to the 2-diethylaminoethyl-dextran family by aerosol administration. Thirty male BALBC mice, 2 month old, were included and divided into three groups. However, pathological findings indicated severe emphysema within three aerosol sessions. In addition, the CytoViva technique was applied for the first time to display the nonviral particles within the pulmonary tissue and emphysema lesions, and a spectral library of the nonviral vector was also established. Although our results in BALBC mice prevented us from further investigation of the DDMC nonviral vector as a vehicle for gene therapy, further investigation in animals with larger airways is warranted to properly evaluate the safety of the vector.

Optimization of non-viral gene transfer to human primary retinal pigment epithelial cells.

PURPOSE: To optimise the high efficiency, non-viral transfer of DNA to retinal pigment epithelial (RPE) cells in vitro. METHODS: A mammalian expression vector (pcDNA3.1) containing a firefly luciferase (luc) cDNA was used to transfect RPE cells using different chemical methods; calcium phosphate, DEAE-dextran and, liposomes-based transfection techniques. Transfection was optimised for both dose and time of exposure. The efficiency of gene transfer and cytotoxicity was measured 48 hours post-transfection using luciferase and MTT assays, respectively. The percentage of transfected cells (using optimal conditions) was determined with a construct expressing a jellyfish green fluorescent protein (GFP) using flow cytometery. RESULTS: Calcium phosphate and DEAE-dextran techniques failed to transfect the vector and led to high cytotoxicity. Liposomes-based methods successfully transferred the vector to RPE cells, but the efficiency varied for different liposomes; Tfx-50 > Lipofectin > Lipofectamine > Cellfectin > DMRIE-C. No significant cytotoxicity was observed with any of the liposome treatments. Optimal transfection was achieved with Tfx-50 at a 3:1 ratio of DNA:liposome; between 12-15% of cells being transfected. CONCLUSIONS: Efficient and non-toxic transfer of functional genes into primary RPE cells in vitro can be successfuly achieved by liposomes-based techniques. Tfx-50 appears to be a promising non-viral vector for RPE gene transfer.

Bovine respiratory syncytial virus infection of bovine embryonic lung cultures: enhancement of infectivity with diethylaminoethyl-dextran and virus-infected cells.

The effects of incorporating diethylaminoethyl-dextran (DEAE-D) in the inoculum with bovine respiratory syncytial virus (BRSV) on the infectivity of BRSV was evaluated. A concentration of 40 microgram DEAE-D/ml provided maximal enhancement of infection as determined by the time of onset of cytopathic effect (CPE), the percentage of cells infected by the inoculum, and the amount of virus produced. When DEAE-D was used in the inoculum, the CPE appeared a day earlier, the percentage of cells infected by the inoculum, as determined by the fluorescent antibody test, was increased 11 times, and the viral titer was increased 2 times as compared to results obtained without DEAE-D. Bovine respiratory syncytial virus-infected cultures contained much cell-associated virus which could be liberated by sonication to increase the titer of virus stocks. The use of BRSV-infected cells rather than supernates from BRSV-infected cells increased the rate at which a cytopathic effect developed, although it did not substantially increase the titer of virus which was harvested. The use of DEAE-D in the inoculum and the passage of BRSV-infected cells instead of viral suspensions was found to be the quickest and most effective method of consistently obtaining BRSV with a titer of about 10(5.5) TCID50/ml.

Innocuity and toxicity testing of non-viral components of foot-and-mouth disease vaccines.

Some biological properties of 3 different adjuvants: saponin, DEAE-dextran and sodium azide applied in foot-and-mouth vaccines have been studied. As tested in guinea pigs, by dialysis of various batches of saponin, the author succeeded in reducing their toxicity by 80 to 90%, their hemolytic activity by 60 to 75% and their inflammatory capacity by 40 to 50%, whereas in cattle the inflammatory capacity of dialyzed saponin batches decreased by 80 to 90%. The inflammatory capacity of DEAE-dextran is about 50 to 60% less than that of the saponin. The effect of saponin and sodium azide has directly been studied in virus suspension also. Neither the saponin nor the sodium azide affected adversely the infectivity and immunogenicity of the antigen. The loss of potency due to the storage of the vaccine is not in relationship with the presence of the two above-named components.