Cindy Gunawan

Catalytic nanomedicine represents an attractive therapeutic approach for cancer therapy while heavily relying on the catalytic activity and tumor selectivity of the catalyst. Here, a novel catalytic biohybrid ("bacterobot") of gold nanoparticle-coated electroactive bacterium is developed for enhanced catalytic cancer therapy. The electroactive G. sulfurreducens, for the first time used in cancer therapy, turbocharges the multienzyme-like catalytic activities of biosynthetic gold nanoparticles via cascade catalytic reactions to produce abundant reactive oxygen species to induce apoptosis and pyroptosis of tumor cells. Distinctive tumor accumulation and a tumor inhibition rate of 68% were achieved with single-dose intravenous injection of biohybrids in 4T1 tumor-bearing mice. Overall, the bacterobot biohybrid therapy demonstrates a high degree of therapeutic selectivity to tumor tissues and consequent excellent therapeutic efficacy and systemic biosafety, signifying the potential to create a paradigm shift in the way cancers are treated.

This research provides molecular insights into the evolutionarily adapted defense mechanisms of a bacterial pathogen against the complex antimicrobial activity of silver nanoparticles at the transcriptional level. The Gram-negative, biofilm-forming bacterium Acinetobacter baumannii upregulated outer membrane proteins along with genes involved in membrane and capsule synthesis, suggestive of enhanced cell surface defense. An increase in surface-attached biofilm colonies in nanosilver-resistant A. baumannii (NAg ^R ) appeared to be associated with enhanced cell membrane integrity and a greater production of extracellular polymeric substances (EPS), the matrix that protects the resident colony. In response to reactive oxygen species (ROS), a recognized toxicity characteristic of the nanoparticle, NAg ^R upregulated its oxidative stress management system, specifically involving ROS scavenger enzymes and opportunistic metal efflux pumps. Majority of these modified defense mechanisms manifested in the resistant bacterium, while absent in the wild-type strain. This study also details the unique defenses of an ionic silver-tolerant A. baumannii (Ag ^T ) variant, which evolved from the same parental strain as NAg ^R . Despite similarities in cell surface and biofilm defense traits, the slower-to-kill tolerant strain exclusively upregulated multidrug efflux systems and respiratory chain enzymes, thought to maintain enhanced respiratory activity, a reported tolerance characteristic. While these findings would benefit from further validating experimental work, identification of these stable defense mechanisms can help better elucidate the complex nature of bacterial NAg adaptation phenomena.

This research explores the adaptive defense mechanisms of a nanosilver-resistant pathogen (NAg ^R ) to protect and fight off the complex antimicrobial targeting of silver nanoparticles. The Gram-negative bacterium Acinetobacter baumannii upregulated expression of outer membrane proteins for cell surface defense, as well as membrane and capsule synthesis genes. Increased abundance of surface-attached biofilm colonies in NAg ^R was linked to the phenotypically indicated increase in membrane integrity, with the bacterium also forming more EPS, the biopolymer matrix that protects the residing colony. In response to the known reactive oxygen species (ROS) toxicity characteristics of the nanoparticle, NAg ^R upregulated its oxidative stress management system, specifically involving ROS scavenger enzymes and opportunistic metal efflux pumps. Many of these evolved defense mechanisms only manifested in the resistant bacterium, while they were absent in the wild-type strain. This study also details the unique defenses of an ionic silver-adapted A. baumannii variant, having evolved from the same wild-type parental strain as NAg ^R . Despite similarities in cell surface and biofilm defense trends, the slower-to-kill tolerant strain (Ag ^T ) exclusively upregulated multidrug efflux systems and respiratory chain enzymes, thought to maintain enhanced respiration activity, a known tolerant characteristic. Identification of these stable defense mechanisms can recommend strategies for molecular targeting to overcome the adaptation phenomena.

Bioinspired nanotopography artificially fabricated on titanium surfaces offers a solution for the rising issue of postoperative infections within orthopedics. On a small scale, hydrothermal etching has proven to deliver an effective antimicrobial nanospike surface. However, translation to an industrial setting is limited by the elevated synthesis temperature (150 °C) and associated equipment requirements. Here, for the first time, we fabricate surface nanostructures using comparatively milder synthesis temperatures (75 °C), which deliver physicochemical properties and antimicrobial capability comparable to the high-temperature surface. Using a KOH etchant, the simultaneous formation of titania and titanate crystals at both temperatures produces a one-dimensional nanostructure array. Analysis indicated that the formation mechanism comprises dissolution and reprecipitation processes, identifying the deposited titanates as hydrated layered tetra-titanates (K₂Ti₄O₉·nH₂O). A proposed nanospike formation mechanism was confirmed through the identification of a core and outer shell for individual nanostructures, primarily comprised of titanates and titania, respectively. Etching conditions dictated crystalline formation, favoring a thicker titanate core for nanorods under higher synthesis temperatures and etchant concentrations. A bactericidal investigation showed the efficacy against Gram-negative bacteria for a representative low-temperature nanosurface (34.4 ± 14.4%) was comparable to the higher temperature nanosurface (34.0 ± 17.0%), illustrating the potential of low-temperature hydrothermal synthesis. Our results provide valuable insight into the applicability of low-temperature etching protocols that are more favorable in large-scale manufacturing settings.

The antimicrobial properties of copper are well-known but maintaining a low oxidation state of Cu in particles is difficult. Herein, antimicrobial Cu_xP particles were synthesized through phosphorization of Cu(OH)₂, to lock copper in its monovalent state (as Cu₃P). We found that the phosphorization could be achieved at temperatures as low as 200C, with stable surface presence of Cu(I) on the resulting Cu_xP particles. Cu(I) can act as a one-electron reducing agent for molecular oxygen, to generate the highly reactive hydroxyl radical. In this study, Cu_xP displayed antibacterial activities on the Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli, with minimum inhibitory concentrations of 32mg/L for the highest temperature particles (350C) on both model bacteria. The evident membrane damage is consistent with the intended hydroxyl radical bacterial targeting mechanism. Low-temperature Cu_xP, although exhibiting lower antibacterial efficacies than those of the higher temperature variant, still showed competitive growth inhibiting activities when compared to other reported antimicrobial copper-based particles. The present work showcases advancements in particle technology that can lead to the development of a more robust antimicrobial agent, presenting a potent additive for self-disinfection applications.

Several recent studies have reported on the development of bacterial resistance to broad-spectrum antimicrobial silver nanoparticles (nanosilver; NAg). NAg is currently one of the most important alternative antimicrobial agents.

The purpose of this study is to evaluate the literature for research trends on cerium oxide from 1990 to 2020 and identify gaps in knowledge in the emerging application(s) of CeONP. Bibliometric methods were used to identify themes in database searches from PubMed, Scopus and Web of Science Core Collection using SWIFT-Review, VOSviewer and SciMAT software programs. A systematic review was completed on published cerium oxide literature extracted from the Scopus database (n = 17,115), identifying themes relevant to its industrial, environmental and biomedical applications. A total of 172 publications were included in the systematic analysis and categorized into four time periods with research themes identified; “doping additives” (n = 5, 1990–1997), “catalysts” (n = 32, 1998–2005), “reactive oxygen species” (n = 66, 2006–2013) and “pathology” (n = 69, 2014–2020). China and the USA showed the highest number of citations and publications for cerium oxide research from 1990 to 2020. Longitudinal analysis showed CeONP has been extensively used for various applications due to its catalytic properties. In conclusion, this study showed the trend in research in CeONP over the past three decades with advancements in nanoparticle engineering like doping, and more recently surface modification or functionalization to further enhanced its antioxidant abilities. As a result of recent nanoparticle engineering developments, research into CeONP biological effects have highlighted its therapeutic potential for a range of human pathologies such as Alzheimer’s disease. Whilst research over the past three decades show the versatility of cerium oxide in industrial and environmental applications, there are still research opportunities to investigate the potential beneficial effects of CeONP in its application(s) on human health.

Recent reports show air pollutant magnetite nanoparticles (MNPs) in the brains of people with Alzheimer's disease (AD). Considering various field applications of MNPs because of developments in nanotechnology, the aim of this study is to identify major trends and data gaps in research on magnetite to allow for relevant environmental and health risk assessment. Herein, a bibliometric and systematic analysis of the published magnetite literature (n = 31 567) between 1990 to 2020 is completed. Following appraisal, publications (n = 244) are grouped into four time periods with the main research theme identified for each as 1990–1997 “oxides,” 1998–2005 “ferric oxide,” 2006–2013 “pathology,” and 2014–2020 “animal model.” Magnetite formation and catalytic activity dominate the first two time periods, with the last two focusing on the exploitation of nanoparticle engineering. Japan and China have the highest number of citations for articles published. Longitudinal analysis indicates that magnetite research for the past 30 years shifted from environmental and industrial applications, to biomedical and its potential toxic effects. Therefore, whilst this study presents the research profile of different countries, the development in research on MNPs, it also reveals that further studies on the effects of MNPs on human health is much needed.

SMP Kristen Petra 2 adalah SMP swasta yang ada di Surabaya. SMP ini memiliki program sekolah entrepreneur yang mengajarkan bagaimana menghasilkan keuntungan, salah satu caranya dengan menghemat energi yang digunakan. Cara menghemat energi ini bisa dengan menggunakan solar panel. Tidak dipungkiri bahwa pada rangkaian solar panel akan mengalami gangguan jika tidak dilakukan maintenance secara rutin. Maka dari itu dibuatlah sebuah alat yang dapat membaca dan memantau arus dan tegangan yang dapat dipantau dari jarak yang jauh yaitu sebuah sistem monitoring. Sistem ini menggunakan 3 buah sensor dimana terdapat 2 sensor arus dan 1 sensor tegangan. Semua Sensor yang terpasang dikendalikan oleh alat mikrokontroler ESP32. Mikrokontroler ini difungsikan untuk menerima, mengelola dan mengirim data dari pembacaan sensor. Hasil dari pembacaan ditampilkan dalam web dan juga dalam LCD yang telah terpasang. Sebelum memasang sensor dilakukan Pengujian dalam pembacaan sensor dengan melakukan beberapa percobaan yaitu dengan memberikan beberapa macam beban yang berbeda-beda (untuk sensor arus) dan beberapa macam sumber tegangan yang berbeda-beda (untuk sensor tegangan). Hasil yang diperoleh dari percobaan adalah sensor arus memiliki selisih pembacaan 0.5A-0.6A sensor ini tidak dapat membaca arus di bawah 1A. Hasil pengujian sensor tegangan memiliki selisih pembacaan 0.73V sensor ini tidak dapat membaca tegangan dibawah 0.73V. Kata Kunci: Solar Panel, ESP32, Sensor Tegangan DC, Sensor Arus ACS712, Modul I2C, Buzzer.