Chitosan nanoparticle (nanochitosan) has a broad antimicrobial spectrum against diverse pathogenic microorganisms. However, its effect on dental caries-associated microorganisms, such as Streptococcus mutans and Candida albicans is yet to be explored. These microorganisms are known for causing early childhood caries. Therefore, this study was aimed at investigating nanochitosan inhibition capacity against dual-species biofilms of S. mutans and C. albicans. In this study, nanochitosan antimicrobial activity is reported against mono and dual biofilm species of S. mutans and/or C. albicans at 3 and 18 h incubation time. Nanochitosan inhibition capacity was observed through biofilm mass quantity and cell viability. The present study successfully synthesized nanochitosan with average diameter of approximately 20–30 nm, and also established dual-species biofilms of S. mutans and C. albicans in vitro. With nanochitosan treatment, the cell viability of both microorganisms significantly decreased with the increasing concentration of nanochitosan. There was no significant decrease in biofilm mass both in the dual and single-species biofilms after 3 h of incubation. However, greater inhibition of biofilm was observed at 18 h incubation.

Chitosan has been a popular option for tissue engineering, however exhibits limited function for bone regeneration due to its low mechanical robustness and non-osteogenic inductivity. Here we hybridized chitosan with TiO₂ nanoparticles to improve its bone regeneration capability. Morphology and crystallographic analysis showed that TiO₂ nanoparticles in anatase-type were distributed evenly on the surface of the chitosan sponges. Degradation test showed a significant effect of TiO₂ nanoparticles addition in retaining its integrity. Biomineralization assay using simulated body fluid showed apatite formation in sponges surface as denoted by PO^4- band observed in FTIR results. qPCR analysis supported chitosan - TiO₂ sponges in bone regeneration capability as indicated by DMP1 and OCN gene upregulation in TiO₂ treated group. Finally, cytotoxicity analysis supported the fact that TiO₂ nanoparticles added sponges were proved to be biocompatible. Results suggest that chitosan-50% TiO₂ nanoparticles sponges could be a potential novel scaffold for bone tissue engineering.

Tanaman Jati (Tectona grandis linn. F) umumnya hanya dimanfaatkan bagian kayunya untuk industri meubel, namun bagian lain seperti daun kurang dimanfaatkan. Daun jati terutama bagian pucuk daun muda dapat menghasilkan pigmen. Produksi serbuk nano pigmen dari daun jati dan karakterisasi serbuk nano pigmen tersebut belum dilakukan. Tujuan penelitian ini adalah menghasilkan nano pigmen dari pucuk daun jati muda dalam bentuk serbuk dengan menggunakan persentase filler yang berbeda dan melakukan karakterisasi serbuk nano pigmen jati tersebut. Pucuk daun jati muda diberi perlakuan mekanik dengan penggerusan kemudian disaring, larutan yang diperoleh diukur partikelnya dengan Particle Size Analyzer (PSA), dan dikeringkan dengan penambahan filler maltodekstrin 5% dan 10%. Serbuk yang diperoleh dihitung rendemen, ukuran partikel, dan kelarutan dalam air. Warna merah yang dihasilkan dari filtrat pucuk daun jati muda berasal dari zat warna antosianin yang terkandung dalam daun jati muda. Ekstrak dari pucuk daun jati muda memiliki ukuran dengan kisaran 87,8- 318,1 nm dengan ukuran rata-rata 109,2 nm. Hal ini menunjukkan bahwa ekstrak tersebut merupakan produk nano di alam. Penambahan filler dengan konsentrasi berbeda berpengaruh terhadap warna, rendemen, ukuran partikel serbuk, dan kelarutan pigmen serbuk dalam air.

A new way to administer platelet-rich plasma (PRP) to improve its viability in more complex and chronic wound healing and soft/hard tissue regeneration in alveolar ridge preservation is demanded. In this study, PRP was encapsulated in chitosan to form a nanosphere with size below 100 nm with an idea to prolong PRP’s growth factors release. Chitosan nanosphere was prepared by ionic gelation method, while PRP was encapsulated by inclusion method. Morphology analysis by transmission electron microscope (TEM) showed that PRP was encapsulated efficiently in the chitosan matrix, making a spherical shape with size of 30–80 nm. Particle size analysis by dynamic Light Scattering (DLS) method further showed that the average size of chitosan—PRP nanosphere was 51.27 ± 33.75 nm, which is a good indication for biomaterials used in body. The stability of the nanoparticle colloid was confirmed with zeta potential score of 50.42 mV. 200 μ l encapsulation of PRP in chitosan nanosphere had the highest encapsulation efficiency, that was further used in total protein release analysis in phosphate buffered saline (PBS) solution. It started with initial burst at 7 h, followed by steady release, then ‘quasi-plateau’ after 96 h (at around 60%), dominated by Korsmeyer-Peppas kinetics model and Fick’s diffusion mechanism. Finally, the nanosphere showed an excellent antibacterial activity against S. mutans as shown from 90.63% bacteria inhibition during assay. The results showed that chitosan—PRP nanosphere could be used as a novel approach for complex/chronic wound healing and soft/hard tissue regeneration following periodontitis treatment or tooth extraction that needs prolonged growth factor release.

This study investigated the relationship between gender, school type, school location, personality, and winning a medal among participants of the two largest student competitions in Indonesia, the National Science Competition (KSN) and the Entrepreneur-based Student National Competition (FIKSI), sponsored by the Indonesian Ministry of Education and Culture. Survey data were collected from 684 participants in KSN and 169 participants in FIKSI. The chi-square test and the logistic regression were employed using Jeffey’s Amazing Statistics Program (JASP) ver. 13. The results revealed a substantial relationship between gender, school location, school type, and personality on winning a medal in KSN, but none in FIKSI. Results also revealed that male participants and participants from Java and private schools were more likely to win medals in KSN than female participants and participants from outside Java and public schools. This study also found that neuroticism has a statistically significant relationship toward receiving a medal in KSN.