Viral and synthetic vectors to deliver nucleic acids were key to the rapid development of extraordinarily efficient COVID-19 vaccines. The four-component lipid nanoparticles (LNPs), containing phospholipids, PEG-conjugated lipids, cholesterol, and ionizable lipids, co-assembled with mRNA via a microfluidic technology, are the leading nonviral delivery vector used by BioNTech/Pfizer and Moderna to access COVID-19 mRNA vaccines. LNPs exhibit a statistical distribution of their four components when delivering mRNA. Here, we report a methodology that involves screening libraries to discover the molecular design principles required to realize organ-targeted mRNA delivery and mediate activity with a one-component ionizable multifunctional amphiphilic Janus dendrimer (IAJD) derived from plant phenolic acids. IAJDs co-assemble with mRNA into monodisperse dendrimersome nanoparticles (DNPs) with predictable dimensions, via the simple injection of their ethanol solution in a buffer. The precise location of the functional groups in one-component IAJDs demonstrated that the targeted organs, including the liver, spleen, lymph nodes, and lung, are selected based on the hydrophilic region, while activity is associated with the hydrophobic domain of IAJDs. These principles, and a mechanistic hypothesis to explain activity, simplify the synthesis of IAJDs, the assembly of DNPs, handling, and storage of vaccines, and reduce price, despite employing renewable plant starting materials. Using simple molecular design principles will lead to increased accessibility to a large diversity of mRNA-based vaccines and nanotherapeutics.
Grafena merupakan nanomaterial yang memiliki konduktivitas tinggi, dapat disintesis dari limbah pelepah sawit dengan komponen dominan selulosa, hemiselulosa dan lignin yang dimanfaatkan sebagai sumber karbon. Penelitian ini bertujuan untuk mengetahui cara sintesis grafena dan karakteristik grafena yang dihasilkan dari limbah pelepah sawit. Metode sintesis grafena secara umum terdiri dari proses karbonisasi, sintesis grafit oksida, kemudian reduksi grafit oksida menjadi grafena. Karbonisasi pelepah sawit menggunakan suhu 300˚C selama 60 menit yang selanjutnya dilakukan pengayakan berukuran 270 mesh. Grafit oksida (GO) disintesis menggunakan metode Hummers yaitu reaksi oksidasi grafit menjadi grafit oksida dengan oksidator berupa KMnO4 dalam suasana asam (H2SO4) yang menghasilkan campuran berwarna coklat tua. Grafit oksida diperoleh sebagai bubuk. Selanjutnya, grafit oksida direduksi menjadi grafena dengan reduktor Zn dalam suasana asam (HCl). Hasil karakterisasi dilakukan dengan perbandingan literatur; hasil XRD menunjukkan hasil berbeda pada difraktogram grafit, grafit oksida dan grafena dengan tingkat kristalinitas yang berkurang. Hasil FTIR menunjukkan adanya gugus fungsional O-H, C=O, ikatan C–OH dan C–O hanya pada grafit dan grafit oksida. Hasil SEM menunjukkan grafena berbentuk lembaran yang lebih tipis dari grafit oksida. Sintesis grafena dari limbah pelepah sawit dapat dilakukan dengan menggunakan metode Reduksi Grafit Oksida (GO) dengan Reduktor Zn.
Premna serratifolia known as bebuas has long been used by Malay comunity for both food and traditional medicine. The most notable advantage of this plant is to heal woman after childbirth and to raise the notion that contains anti-inflammatory bioactive compounds. In this study, the hexane extract of bebuas was only contained steroids. Meanwhile the ethanol extract contained various secondary metabolites such as phenolics, alkaloids, flavonoids, steroids and saponins. The ethanol extract was further separated since the targeted compound isolate was an alkaloid. The isolate obtained was a yellow crystal which transformed to yellow oil after being exposed to air. The anti-inflammatory evaluation of the compound gave a result with a strong activity with ED50 = 4.06 mg/KgBW. Characterization by UV-Vis and FT-IR showed that the isolate’s spectra pattern had similarities with bufotenine. It revealed that the isolate shared the same basic skeleton with the bufotenine, especially the indole skeleton. Furthermore, it also shared the same physical form with bufotenine. These evidences strengthened the assumption that the isolate was an indole alkaloid.
Bebuas (Premna serratifolia) traditionally is used by Malay people as a traditional medicine to restore health. This indicates it contains chemicals that potentially have an anti-inflammatory activity. The results of phytochemical screening showed that the ethanol extract contains phenolics, alkaloids, flavonoids, steroids and saponins. Meanwhile, hexane extract only contains steroids. Anti-inflammatory activity evaluation on crude extracts showed that the ethanol extract was more active than the hexane extract. Therefore, the isolation step was continued to ethanol extract with the targeted compound was an alkaloid. Extraction was conducted by using acid-base and partition techniques to give the alkaloids fraction (EaBW). EaBW is then further separated by liquid vacuum column technique using gradual polarity elution, with eluent of ethyl acetate (Ea) - methanol and obtained 5 fractions. The isolate was obtained from F.3. The isolate showed it had anti-inflammatory activity with ED50 = 5.45 mg/KgBW. The UV-Vis and FT-IR spectra patterns of the isolate have similarities with ciprofloxacin as well as its physical characteristics which are hygroscopic yellowish crystal, and fluorescence property. Therefore, the isolated compound is thought to have a similar structure to ciprofloxacin.
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