The role of nanohydroxyapatite on the morphological, physical, and biological properties of chitosan nanofibers

Objectives This study aimed to evaluate the effects of nanohydroxyapatite (nHAp) particles on the morphological, chemical, physical, and biological properties of chitosan electrospun nanofibers. Materials and methods nHAp particles with a 1.67 Ca/P ratio were synthesized via the aqueous precipitation method, incorporated into chitosan polymer solution (0.5 wt%), and electrospun into nHAp-loaded fibers (ChHa fibers). Neat chitosan fibers (nHAp-free, Ch fibers) were used as the control. The electrospun fiber mats were characterized using morphological, topographical, chemical, thermal, and a range of biological (antibacterial, antibiofilm, cell viability, and alkaline phosphatase [ALP] activity) analyses. Data were analyzed using ANOVA and Tukey’s test (α = 0.05). Results ChHa fibers demonstrated a bead-like morphology, with thinner (331 ± 110 nm) and smoother (Ra = 2.9 ± 0.3 μm) distribution as compared to the control fibers. Despite showing similar cell viability and ALP activity to Ch fibers, the ChHa fibers demonstrated greater antibacterial potential against most tested bacteria (except for P. intermedia), and higher antibiofilm activity against P. gingivalis biofilm. Conclusions The incorporation of nHAp particles did not jeopardize the overall morphology, topography, physical, and biological characteristics of the chitosan nanofibers. Clinical relevance The combination of nHAp particles with chitosan can be used to engineer bioactive, electrospun composite nanofibers with potential applications in regenerative dentistry

Klebsiella pneumoniae Planktonic and Biofilm Reduction by Different Plant Extracts: In Vitro Study

This study evaluated the action of Pfaffia paniculata K., Juglans regia L., and Rosmarius officinalis L. extracts against planktonic form and biofilm of Klebsiella pneumoniae (ATCC 4352). Minimum inhibitory concentration (MIC) and minimum microbicidal concentration (MMC) values were determined for each extract by microdilution broth method, according to Clinical and Laboratory Standards Institute. Next, antimicrobial activity of the extracts on biofilm was analyzed. For this, standardized suspension at 10 7 UFC/mL of K. pneumoniae was distributed into 96-well microplates ( = 10) and after 48 h at 37 ∘ C and biofilm was subjected to treatment for 5 min with the extracts at a concentration of 200 mg/mL. ANOVA and Tukey tests (5%) were used to verify statistical significant reduction ( < 0.05) of planktonic form and biofilm. P paniculata K., R. officinalis L., and J. regia L. showed reductions in biomass of 55.6, 58.1, and 18.65% and cell viability reduction of 72.4, 65.1, and 31.5%, respectively. The reduction obtained with P. paniculata and R. officinalis extracts was similar to the reduction obtained with chlorhexidine digluconate 2%. In conclusion, all extracts have microbicidal action on the planktonic form but only P. paniculata K. and R. officinalis L. were effective against biofilm