Introduction of tenomodulin by gene transfection vectors for rat bone tissue regeneration

Introduction

Periodontal ligament is regenerated in association with hard tissue regeneration. Tenomodulin (Tnmd) expression has been confirmed in periodontal ligament and it reportedly inhibits angiogenesis or is involved in collagen fibril maturation. The introduction of Tnmd by gene transfection in bone tissue regeneration therapy might inhibit topical hard tissue formation and induce the formation of dense fibrous tissue. Therefore, the effect of Tnmd introduction by gene transfection technique in vitro and in vivo was investigated in this study.

Methods

Osteogenesis- and chondrogenesis-related gene expression levels in osteoblastic cells (MC3T3E1) and rat bone marrow derived cells were detected using qPCR three days after gene transfection with plasmid DNA (Tnmd) using non-viral gene transfection vectors: a calcium phosphate-based gene transfection vector (CaP(Tnmd)) or a cationic polymer-based reagent (JetPEI (Tnmd)). Next, an atelocollagen scaffold with or without CaP (Tnmd) or JetPEI (Tnmd) was implanted into a rat calvaria bone defect, and the remaining bone defect volume and the tissue reaction at 28 days after surgery were evaluated.

Results

Runx 2 and SP7 mRNA was reduced by JetPEI (Tnmd) in both cells, but not in CaP(Tnmd). The volume of expressed Tnmd was at 9 ng/mL in both gene transfection vector. The remaining bone defect volume of JetPEI (Tnmd) was significantly bigger than that of the other groups and CaP (EGFP), and that of CaP (Tnmd) was significantly bigger than that of CaP (EGFP).

Conclusions

Tnmd introduction treatment inhibits bone formation in artificial bone defect, however, the effect of that was dependent on non-viral gene transfection vector.

Oral delivery of proteins and peptides: Challenges, status quo and future perspectives

Proteins and peptides (PPs) have gradually become more attractive therapeutic molecules than small molecular drugs due to their high selectivity and efficacy, but fewer side effects. Owing to the poor stability and limited permeability through gastrointestinal (GI) tract and epithelia, the therapeutic PPs are usually administered by parenteral route. Given the big demand for oral administration in clinical use, a variety of researches focused on developing new technologies to overcome GI barriers of PPs, such as enteric coating, enzyme inhibitors, permeation enhancers, nanoparticles, as well as intestinal microdevices. Some new technologies have been developed under clinical trials and even on the market. This review summarizes the history, the physiological barriers and the overcoming approaches, current clinical and preclinical technologies, and future prospects of oral delivery of PPs.

Stone formation in the Middle Eastern Gulf States: A review

Objectives

To review the possible causes of the high incidence of urolithiasis in the oil-rich Gulf States.

Methods

Data were extracted from published reports on the incidence of urolithiasis, affluence and diet in the Gulf States, various Western countries and China.

Results

There are strong relationships: (a) between the life-expectancy of stones in men and the Gross National Income (GNI) per capita of these countries; and (b) between the daily consumption of animal protein and GNI per capita. Together these data suggest that the occurrence of stones is proportional to the intake of animal protein, although they also indicate that there are additional factors that further increase the risk of urolithiasis in the populations of the Gulf. The consumption of oxalate in the Gulf is three times higher and that of calcium a half of what it is in Western countries. Thus, the average oxalate/calcium ratio in the intestines of the Gulf populations is five to six times higher than that in Western populations, leading to enteric hyperoxaluria and an increased risk of calcium-oxalate stone formation. The risk is further accentuated by the lower urine volumes, due to the hot, dry climate of the region, and lower excretions of citrate, from the highly acidic urine resulting from the high intake of animal protein. There is a high incidence of uric acid-containing stones from the acidic urine and the hyperuricosuria caused by the high intake of purine.

Conclusions

The high incidence of urolithiasis in the Gulf is due to an adverse combination of dietary and environmental factors.

Methods for diagnosing the risk factors of stone formation

OBJECTIVE

To compare various systems for assessing the risk of recurrent stones, based on the composition of urine.

METHODS

The relative supersaturation (RSS) of urine, the Tiselius Indices, the Robertson Risk Factor Algorithms (RRFA) and the BONN-Risk Index were compared in terms of the numbers of variables required to be measured, the ease of use of the system and the value of the information obtained.

RESULTS

The RSS methods require up to 14 analyses in every urine sample but measure the RSS of all the main constituents of kidney stones. The Tiselius Indices and the RRFA require only seven analyses. The Tiselius Indices yield information on the crystallisation potentials (CP) of calcium oxalate and calcium phosphate; the RRFA also provide information on the CP of uric acid. Both methods provide details on the particular urinary abnormalities that lead to the abnormal CP of that urine. The BONN-Risk Index requires two measurements in each urine sample but only provides information on the CP of calcium oxalate. Additional measurements in urine have to be made to identify the cause of any abnormality.

CONCLUSIONS

The methods that are based on measuring RSS are work-intensive and unsuitable for the routine screening of patients. The Tiselius Indices and the RRFA are equally good at predicting the risk of a patient forming further stones. The BONN-Risk Index provides no additional information about the causative factors for any abnormality detected.