Micro and Nanosystems - Volume 17, Issue 2, 2025

The development of more effective drug delivery techniques is necessary to increase treatment efficacy and patient compliance since tuberculosis (TB) is still a serious worldwide health concern. Ethambutol is a vital aspect of TB treatment, and using nanoparticles to carry it to the lungs may provide targeted delivery and prolonged release, which might enhance the effectiveness of the treatment.

This work aimed to optimize the formulation for prolonged drug release by synthesizing and assessing ethambutol-loaded nanoparticles using the desolation technique with albumin as the polymer. Additionally, the effects of different drug-polymer ratios and stirring rates were investigated.

Nine formulations of ethambutol-loaded nanoparticles were prepared by varying the drug-polymer ratios (1:1 to 1:2) and stirring speeds (500 to 1500 rpm). Key parameters, such as particle size, drug entrapment efficiency, and zeta potential, were measured. The optimized formulation was selected based on the smallest particle size and highest drug entrapment efficiency. Scanning electron microscopy was used to analyze the surface morphology of the nanoparticles. The in vitro drug release profile of the optimized formulation was studied over 24 hours.

Increasing the drug-polymer ratio from 1:1 to 1:2 increased nanoparticle size from 192.1 nm to 605.06 nm and decreased drug entrapment efficiency from 75.7% ± 0.08 to 34% ± 0.06. Higher stirring speeds (500 to 1500 rpm) also led to larger particle sizes and reduced drug entrapment due to polymer self-aggregation. Zeta potential values ranged from -5.56 to -25.6 mV. Scanning electron microscopy confirmed smooth, spherical nanoparticles. The optimized formulation, EN-5, exhibited the smallest particle size and highest drug entrapment efficiency. In vitro drug release studies showed a sustained ethambutol release, with 42.66 ± 1.53% released in 12 hours and 79.082 ± 2.98% in 24 hours.

Ethambutol-loaded nanoparticles having the ability to transport drugs to the lungs over an extended period of time were developed and optimized in the study. With improved drug delivery systems, the optimized formulation showed notable drug entrapment efficiency and controlled release, suggesting its potential to improve tuberculosis therapy.

Many applications, including biological applications, require a very high output impedance current mirror because they run at very low voltages. The circuit known as the current mirror applies the idea that two identical MOS transistors with the same gate-source voltage will have equal channel currents flowing through them.

The objective of this study is to optimize the design to minimize power consumption while maintaining accurate current mirroring, which is crucial for low-power and energy-efficient electronic systems.

This study is performed in Cadence Virtuoso using the gdpk45 technology node to construct a cascode current mirror, comparing simulation findings to other contemporary mirrors.

A significant improvement in power usage is shown in comparison to other types of current mirrors, and a small signal model analysis of the circuit, the design, and its mathematical model is investigated.

Compared to the circuits that were previously designed, the output resistance values are substantially greater. The cascode current mirror that is suggested in this paper uses 48 µW of electricity, while the other cascode current mirror uses 74.186 µW.

The synthesis of carbon quantum dots (CQDs) from Basella alba L. fruit using the hydrothermal method is investigated for heavy-metal detection. CQDs have gained significant attention due to their unique properties, including high photoluminescence, biocompatibility, and low toxicity. The utilization of natural sources such as Basella alba L. fruit for CQDs synthesis offers an eco-friendly and cost-effective approach.

In this study, Basella alba L. fruit was chosen as a precursor for CQDs synthesis due to its abundance and potential for heavy-metal adsorption. The hydrothermal method was employed as it provides a simple and efficient route for CQDs synthesis. The process involves the hydrolysis and carbonization of the fruit extract under controlled temperature and pressure conditions. The resulting CQDs were characterized using various techniques such as UV-visible spectroscopy, FE-SEM, EDS, E-mapping, DLS, Zeta potential, PL spectroscopy, and FTIR.

UV-Vis confirmed the presence of CQDs via the observation of a distinct absorption peak. EDS spectrum revealed the formation of CQDs and other groups of elements present with it, which contribute to their stability and interaction with heavy metals. FESEM images showed that the synthesized CQDs possessed a uniform size distribution and exhibited a well-defined crystalline structure. The synthesized CQDs were then evaluated for heavy-metal detection. In addition, due to their unique surface properties and interaction with heavy metals, CQDs acted as an effective sensor. A series of experiments were conducted to investigate the sensitivity and selectivity of the CQDs towards various metal ions. The results demonstrated the superior performance of the synthesized CQDs in detecting Fe³⁺ ions, exhibiting high sensitivity and selectivity by quenching fluorescence when interacting with Fe³⁺ ions.

The successful synthesis of CQDs from Basella alba L. fruit is reported. The characterization results confirmed the formation of CQDs with desirable properties for Fe³⁺ ions detection. The obtained CQDs demonstrated promising potential as efficient and eco-friendly sensors for Fe³⁺ ions detection in environmental and biomedical samples.

Acyclovir, a BCS class III drug (that has high solubility and low permeability) is an antiviral drug used for the treatment of herpes simplex and varicose zoster. To enhance acyclovir's permeability across the intestinal membrane and to improve its bioavailability the β-cyclodextrin (β-CD) nanoparticles of acyclovir were prepared with sodium lauryl sulfate (SLS) as a crosslinking agent.

A phase solubility study was performed with varying ratios of acyclovir to β-CD. Three formulations of acyclovir-loaded β-CD nanoparticles were prepared with drug-β-CD ratios of 1:1, 1:2, and 1:4. The prepared nanoparticle formulations were characterized for FTIR, dynamic light scattering (particle size, polydispersity index, zeta potential) and in vitro permeability studies.

Phase solubility study resulted in an “AL type” curve with an association constant (Kc) of 12 M^-1 which suggested the formation of a strong complex between acyclovir and β-CD, leading to enhanced solubility of acyclovir with increasing concentrations of β-CD. The FTIR spectrum confirmed the compatibility of acyclovir, β-CD, and SLS in the formulations. Dynamic light scattering analysis demonstrated particle sizes ranging from 152.92 nm to 335.7 nm, with the smallest particles in the 1:4 ratio formulation (152.92 nm), potentially due to higher drug encapsulation. Zeta potential measurements reflected formation of stable nanoparticle suspensions, with the formulation exhibiting a zeta potential of -45.4 mV showcasing optimal stability. In vitro permeation studies revealed that the 1:4 ratio formulation exhibited the highest permeability (84.24 ± 1.94% at the end of 150 min) through the eggshell membrane, implying efficient drug release. This increase in permeability corroborated with its smallest particle size.

The study highlights the potential of β-CD nanoparticles (with best performance shown by drug-to-β-CD ratio 1:4) in augmenting acyclovir's delivery, suggesting a promising avenue for improving the drug delivery in viral infections.

QCA nanotechnology is an emerging technology in the current scenario to develop the digital circuits for area-efficient, energy-efficient, low-power, and high-speed applications. The EXOR gate is broadly used in many digital applications. Therefore, an EXOR gate needs to be designed in an emerging technology to tackle the issues of the nanoscale regime of conventional metal oxide semiconductor (MOS) technology.

This study aims to implement an efficient 3-input exclusive OR (EXOR) gate using quantum-dot cellular automata (QCA) nanotechnology and check its performance for subsequent circuits.

The objective of this research work is to develop an efficient translation-based 3-input EXOR gate in QCA nanotechnology. The subsequent circuits are designed using the proposed EXOR gate to evaluate the efficacy of extension work.

A unique feature of QCA nanotechnology is utilized for the design of the EXOR gate. The translation-based approach is applied for the implementation of the proposed EXOR gate. A QCA cell may be shifted from its initial position in order to form the logic function. The translation-based method saves the area requirement.

The proposed EXOR gate consists of only 10 QCA cells and 0.50 clocks. The energy dissipation and fault analyses are done for the proposed EXOR gate. A thorough comparative study is prepared for the performance evaluation. The various subsequent circuits, such as a full adder, a 4-bit parity checker, and a 4-bit binary to gray (BTG) code converter, are also designed using the proposed EXOR gate in order to check the extension work on the proposed EXOR gate.

It is observed from the simulation work on the proposed EXOR gate that it saves layout area and is most cost-effective. It is highly optimized in terms of cell count and clock. The proposed EXOR gate saves 25% cell area and 23.08% design cost as compared to the best-reported design. The designed subsequent circuits also outperform in terms of different parameters. The full adder reduces 33.33% cell count and 34.85% cost as compared to the best-reported design. The 4-bit parity checker improves the cell count by 47.50% and the design cost by 57.29% as compared to the best-reported work. The 4-bit BTG code converter minimizes layout area by 25.81% and design cost by 29.30% as compared to the best-reported work.