Abstract Acne Vulgaris is a common skin disease caused by Propionibacterium acnes, an anaerobic microbiota of human skin that plays a vital role in the pathology of acne. The aim of this study was to prepare nanoparticles containing an acne recombinant protein and determine its ability as an oral acne vaccine in mice. The recombinant Sialidase-CAMP gene was expressed and purified in a prokaryotic host. The chitosan nanoparticles containing the recombinant protein were prepared, encapsulated, and administered by both oral and subcutaneous routes to Balb/c mice. Sera IgA and IgG and stool IgA titers were measured by ELISA, and the immunized mice were challenged against P. acnes. A 65 kDa recombinant protein was confirmed by SDS-PAGE and western blot. The size and zeta potential of nanoparticles were 80 nm and +18 mV, respectively. After oral immunization, the serum IgG and IgA titers were 1:3200 and 1:16, respectively, and the stool IgA titer was 1:8. In the subcutaneous route, the serum IgG titer was 1:51200. Immunized mice showed no inflammation in the ear of challenged mice. It is the first study that examines a chitosan-nanoparticulated acne fusion protein as an applicable acne vaccine candidate with appropriate immunogenicity potential. Further studies are required to validate the clinical usefulness of this vaccine candidate.

The energetic, geometric, and electronic structure of Li-adsorbed pristine, B- and N-doped carbon nanocones (B- and N-CNCs) were investigated by means of density functional theory. It was found that Li atom is strongly adsorbed above the center of pentagonal ring of the pristine CNC with the adsorption energy of −1.08 eV (at B3LYP/6-31G(d)) along with the charge transfer from Li to the CNC. After this process, the semiconductive CNC is transformed to an n-type one, so that its HOMO-LUMO energy gap (Eg) is reduced from 2.51 to 0.71 eV (at B3LYP/6-31G(d)). Doping semiconductive CNC with B or N atom also creates a p- or n-type semiconductive material, resulting in an increased conductance. B-doping improves the Li adsorption on the CNC, while N-doping hinders this process. It seems that Li atom acts as an electron-donor agent with n-type effect, and therefore, its adsorption on the B-CNC somewhat compensates the p-type effect of B-doping. On the contrary, the adsorption process on the N-CNC moderately promotes the n-type effect of N-doping, leading to more reduction in the Eg value.

La energética, así como las estructuras geométricas y electrónicas de Li adsorbido en nanoconos de carbono puros y dopados con B y N (B- and N-CNCs) se investigan por medio de la teoría de funcionales de la densidad. Se encontró que el átomo de Li se adsorbe fuertemente sobre el centro de un anillo pentagonal de un CNC puro con una energía de adsorción de −1.08 eV (utilizando B3LYP/6-31G(d)), junto con una transferencia de carga del Li al CNC. Después de este proceso, el CNC semiconductor se transforma en uno de tipo-n, de manera que la brecha de energía HOMO-LUMO (Eg) se redujo de 2.51 a 0.71 eV (utilizando B3LYP/6-31G(d)). Al dopar el CNC semiconductor con B o N también crea un material semicoductor tipo-p y -n, incrementando su conductancia. El dopaje con B mejora la adsorción de Li en el CNC, mientras que el dopaje con N dificulta este proceso. Parece que el átomo de Li actúa como un agente electrodonador con un efecto tipo-n, y por tanto, su adsorción sobre el B-CNC de alguna manera compensa el efecto tipo-p del dopaje con B. Por el contrario, el proceso de adsorción sobre el N-CNC promueve moderadamente el efecto tipo-n del dopaje con N, lo que lleva a una mayor reducción en el valor de Eg.