ABSTRACT
Hydrogel-based regenerative endodontic procedures (REPs) are considered to be very promising therapeutic strategies to reconstruct the dental pulp (DP) tissue in devitalized human teeth. However, the success of the regeneration process is limited by residual bacteria that may persist in the endodontic space after the disinfection step and contaminate the biomaterial. The aim of this work was to develop an innovative fibrin hydrogel incorporating clindamycin (CLIN)-loaded Poly (d,l) Lactic Acid (PLA) nanoparticles (NPs) to provide the hydrogel with antibacterial properties. CLIN-PLA-NPs were synthesized by a surfactant-free nanoprecipitation method and their microphysical properties were assessed by dynamic light scattering, electrophoretic mobility and scanning electron microscopy. Their antimicrobial efficacy was evaluated on Enteroccocus fæcalis by the determination of the minimal inhibitory concentration (MIC) and the minimal biofilm inhibition and eradication concentrations (MBIC and MBEC). Antibacterial properties of the nanocomposite hydrogel were verified by agar diffusion assays. NP distribution into the hydrogel and release from it were evaluated using fluorescent PLA-NPs. NP cytotoxicity was assessed on DP mesenchymal stem cells (DP-MSCs) incorporated into the hydrogel. Type I collagen synthesis was investigated after 7 days of culture by immunohistochemistry. We found that CLIN-PLA-NPs displayed a drug loading of 10 ± 2 µg per mg of PLA polymer and an entrapment efficiency of 43 ± 7%. Antibiotic loading did not affect NP size, polydispersity index and zeta potential. The MIC for Enterococcus fæcalis was 32 µg mL-1. MBIC50 and MBEC50 were 4 and 16 µg mL-1, respectively. CLIN-PLA-NPs appeared homogenously distributed throughout the hydrogel. CLIN-PLA-NP-loaded hydrogels clearly inhibited E. faecalis growth. DP-MSC viability and type I collagen synthesis within the fibrin hydrogel were not affected by CLIN-PLA-NPs. In conclusion, CLIN-PLA-NP incorporation into the fibrin hydrogel gave the latter antibacterial and antibiofilm properties without affecting cell viability and function. This formulation could help establish an aseptic environment supporting DP reconstruction and, accordingly, might be a valuable tool for REPs.
Subject(s)
Anti-Bacterial Agents/therapeutic use , Bacterial Infections/prevention & control , Dental Pulp/physiology , Hydrogels/chemistry , Nanocomposites/chemistry , Regeneration/drug effects , Anti-Bacterial Agents/chemistry , Biofilms/drug effects , Clindamycin/chemistry , Clindamycin/therapeutic use , Dental Pulp/cytology , Drug Liberation , Enterococcus faecalis/drug effects , Enterococcus faecalis/physiology , Female , Fibrin/chemistry , Fibrin/toxicity , Humans , Hydrogels/toxicity , Mesenchymal Stem Cells/drug effects , Microbial Sensitivity Tests , Nanocomposites/toxicity , Nanoparticles/chemistry , Nanoparticles/toxicity , Polyesters/chemistry , Polyesters/toxicity , Tissue Engineering/methodsABSTRACT
One of the main goals in the galenic development of innovative topical treatment options for inflammatory skin diseases such as psoriasis and atopic dermatitis is to selectively deliver the drug at the inflammation site. Recent studies have highlighted the beneficial use of polymeric nanoparticles for anti-inflammatory therapy and topical anti-inflammatory drug delivery due to their ability to form a drug reservoir retaining the drug locally at the site of action. Our approach consisted in designing innovative topical semi-solid formulations of poly(lactic acid) (PLA) nanoparticles as anti-inflammatory drug vehicles for local treatment of inflammatory skin diseases. In the course of this work, five topical formulations containing fluorescent PLA nanoparticles were initially developed, and then screened depending on their physico-chemical properties, toxicity and delivery efficacy. The penetration and permeation of a fluorophore vectorized by PLA nanoparticles into healthy and inflammatory skin were assessed using an alternative device to classical Franz cells: VitroPharma. All these investigations led to the selection of two satisfactory formulations out of five initial candidates.
Subject(s)
Anti-Inflammatory Agents/administration & dosage , Anti-Inflammatory Agents/chemistry , Inflammation/drug therapy , Nanoparticles/chemistry , Polyesters/chemistry , Polymers/chemistry , Skin Diseases/drug therapy , Administration, Topical , Animals , Chemistry, Pharmaceutical/methods , Drug Delivery Systems/methods , Male , Mice , Mice, Inbred BALB C , Nanoparticles/administration & dosage , Polyesters/administration & dosage , Polymers/administration & dosage , Skin/drug effects , Skin Absorption/drug effectsABSTRACT
Reciprocal crosses were performed between Brassica napus (AACC, 2n = 38) cv. Brutor and Sinapis alba (SalSal, 2n = 24) cv. Carine. Using fertilized ovary culture, 2.2 and 1.9% of interspecific hybrids were produced when white mustard was the female and the male parent, respectively. On S. alba cytoplasm, three plants with a BC1-like structure (SalSalAC, 2n = 43) were obtained and ACSal (2n = 31) and AACCSal (2n = 50) hybrids on reciprocal crosses. At the same ploidy level, no differences in meiotic behavior were observed. The amphidiploids (AACCSalSal, 2n = 62), produced after colchicine treatment of ACSal hybrids, were compared with the somatic hybrids previously obtained from the same parental varieties. Only two somatic hybrids differed and one of them lost Idh-2 rapeseed isozymes, whereas all the plants presented an hybrid pattern for all the other molecular markers. The plants with 50 chromosomes (AACCSal) from sexual hybrids were similar whatever their origins. Their comparison with back-cross progeny of somatic hybrids revealed that the latter one differed either by chromosome number, ranging from 42 to 54, or by the percentage of cells with less than 12 univalents and with multivalents. From our results, the efficiency of protoplast fusion compared with sexual crosses as a tool to introduce new traits in a crop is discussed.
ABSTRACT
The mitochondrial genomes of five rapeseed somatic hybrid plants, which combine in a first experimentBrassica napus chloroplasts and a cytoplasmic male sterility trait coming fromRaphanus sativus, and in a second experiment chloroplasts of a triazine resistantB. compestris and a cytoplasmic male sterility trait fromR. sativus, were analyzed by restriction endonucleases. Restriction fragment patterns indicate that these genomes differ from each other and from both parents. The presence of new bands in the somatic hybrid mitochondrial DNA restriction patterns is evidence of mitochondrial recombination in somatic hybrid cells. In both parental and somatic hybrid plants large quantitative variations in a mitochondrial plasmid-like DNA have been observed. Our results suggest that the cytoplasmic support for male sterility is located in the chromosomal mitochondrial DNA instead of the plasmid-like DNA.
