Particle shape engineering for improving safety and efficacy of doxorubicin - A case study of rod-shaped carriers in resistant small cell lung cancer

Polymer-Based Designer Particles as Drug Carriers: Strategies to Construct and Modify

Biological barriers present remarkable challenges for therapeutics delivery, requiring an advanced drug delivery system that can navigate through the complex physiological environment. Polymeric particles provide remarkable versatility due to their adaptable physiochemical properties, facilitating new designs that address complex delivery issues. This review focuses on recent advancements in the morphology of polymeric particles that emulate biological barriers to improve drug efficacy. It includes how structural engineering─such as designing rod-shaped particles for improved cellular uptake, red-blood-cell-shaped particles for prolonged circulation, worm-shaped carriers for improved tissue penetration, and multicompartmental systems for providing combination therapies─profoundly alters drug delivery capabilities. These designer particles exhibit enhanced target specificity, controlled release kinetics, and improved therapeutic outcomes relative to traditional spherical carriers. This particular review also emphasizes how a combination of polymer chemistry and fabrication methods facilitates achieving these advanced structures, while highlighting ongoing challenges in scale-up, reproducibility, and clinical translations. Through the analysis of structure-functional property correlations in various biomimetic designs, we have also attempted to provide insight into future advancements in polymeric delivery systems that have the potential to transform treatment strategies for complicated diseases via shape-directed biological interactions for better therapeutic outcomes.

Microfluidics-Assembled Nanovesicles for Nucleic Acid Delivery

Microfluidic technologies have become a highly effective platform for the precise and reproducible production of nanovesicles used in drug and nucleic acid delivery. One of their key advantages lies in the one-step assembly of multidrug delivery nanovesicles, which improves batch-to-batch reproducibility by minimizing the intermediate steps typically required in conventional methods. These steps often involve complex hydrophobic and electrostatic interactions, leading to variability in the nanovesicle composition and performance. Microfluidic systems streamline the encapsulation of diverse therapeutic agents, including hydrophilic nucleic acids, proteins, and both hydrophobic and hydrophilic small molecules, within a single chip, ensuring a more consistent production process. This capability enables the codelivery of multiple drugs targeting different disease pathways, which is particularly valuable in reducing the risk of drug resistance. Despite the promise of nanovesicles for nucleic acid delivery, their clinical translation has been hindered by safety concerns, particularly cytotoxicity, which has overshadowed efforts to improve in vivo stability and delivery efficiency. Positively charged nanovesicles, commonly used to encapsulate negatively charged nucleic acids, tend to exhibit significant cytotoxicity. To address this, charge-shifting materials that respond to pH changes or surface modifications have been proposed as promising strategies. Shifting the surface charge from positive to neutral or negative at physiological pH can reduce the cytotoxicity, enhancing the clinical feasibility of these nanovesicle-based therapies. Microfluidic platforms offer precise control over key nanovesicle properties, including particle size, rigidity, morphology, and encapsulation efficiency. Particle size is relatively easy to adjust by controlling flow rates within microfluidic channels, with higher flow rates generally producing smaller particles. However, continuous tuning of the particle rigidity remains challenging. By manipulation of the interfacial water layer between hydrophobic and amphiphilic components during nanoparticle formation, future designs may achieve greater control over rigidity, which is critical for improving cellular uptake and biodistribution. While shape tuning using microfluidic chips has not yet been fully explored in biomedical applications, advances in materials science may enable this aspect in the future, offering further customization of the nanovesicle properties. The integration of nanovesicle assembly and surface modification within a single microfluidic platform presents challenges due to the differing speeds of these processes. Nanovesicle assembly is typically rapid, whereas surface modifications, such as those involving functional biomolecules, occur more slowly and often require purification steps. Recent advances, such as rotary valve designs and single-axis camshaft mechanisms, offer precise control over flow mixing at different stages of the process, allowing for the automation of nanovesicle assembly and surface modification, thereby improving batch-to-batch reproducibility. In conclusion, microfluidic technologies represent a promising approach for the development of multifunctional nanovesicles with the potential to address key challenges in drug delivery and precision medicine. While obstacles related to cytotoxicity, scalability, and reproducibility remain, innovations in chip design, materials, and automation are paving the way for broader application in clinical settings. Future research, potentially incorporating machine learning, could further optimize the relationship between nanovesicle properties and biological outcomes, advancing the use of microfluidic technologies for therapeutic delivery.

Chitosan/bovine serum albumin layer-by-layer assembled particles for non-invasive inhaled drug delivery to the lungs

Layer-by-Layer (LbL) assembly of polyelectrolytes on a solid core particle is a well-established technique used to deliver drugs, proteins, regenerative medicines, combinatorial therapy, etc. It is a multifunctional delivery system which can be engineered using various core template particles and coating polymers. This study reports the development and in-vitro evaluation of LbL assembled particles for non-invasive inhaled delivery to the lungs. The LbL assembled particles were prepared by successively coating polyelectrolyte macromolecules, glycol chitosan and bovine serum albumin on 0.5- and 4.5-μm polystyrene particles. The LbL assembly of polyelectrolytes was confirmed by reversible change in zeta potential and sequential increase in the particle size after accumulation of the layer. The prepared LbL particles were further assessed for aerodynamic properties using two distinct nebulizers, and toxicity assessment in normal lung cells. The in-vitro aerosolization study performed using next generation impactor coupled with Pari LC Plus and Aeroeclipse nebulizer showed that both the LbL assembled 0.5 and 4.5-μm particles had MMAD <5 μm confirming suitable aerodynamic properties for non-invasive lung delivery. The in-vitro cytotoxicity, and TEER integrity following treatment with the LbL assembled particles in normal lung epithelial and fibroblasts showed no significant cytotoxicity rendering the LbL assembled particles safe. This study extends the efficiency of LbL assembled particles for novel applications towards delivery of small and large molecules into the lungs.

Polymeric Nanoparticles for Drug Delivery

The recent emergence of nanomedicine has revolutionized the therapeutic landscape and necessitated the creation of more sophisticated drug delivery systems. Polymeric nanoparticles sit at the forefront of numerous promising drug delivery designs, due to their unmatched control over physiochemical properties such as size, shape, architecture, charge, and surface functionality. Furthermore, polymeric nanoparticles have the ability to navigate various biological barriers to precisely target specific sites within the body, encapsulate a diverse range of therapeutic cargo and efficiently release this cargo in response to internal and external stimuli. However, despite these remarkable advantages, the presence of polymeric nanoparticles in wider clinical application is minimal. This review will provide a comprehensive understanding of polymeric nanoparticles as drug delivery vehicles. The biological barriers affecting drug delivery will be outlined first, followed by a comprehensive description of the various nanoparticle designs and preparation methods, beginning with the polymers on which they are based. The review will meticulously explore the current performance of polymeric nanoparticles against a myriad of diseases including cancer, viral and bacterial infections, before finally evaluating the advantages and crucial challenges that will determine their wider clinical potential in the decades to come.

Roll-to-roll, high-resolution 3D printing of shape-specific particles

Particle fabrication has attracted recent attention owing to its diverse applications in bioengineering1,2, drug and vaccine delivery3-5, microfluidics6,7, granular systems8,9, self-assembly5,10,11, microelectronics12,13 and abrasives14. Herein we introduce a scalable, high-resolution, 3D printing technique for the fabrication of shape-specific particles based on roll-to-roll continuous liquid interface production (r2rCLIP). We demonstrate r2rCLIP using single-digit, micron-resolution optics in combination with a continuous roll of film (in lieu of a static platform), enabling the rapidly permutable fabrication and harvesting of shape-specific particles from a variety of materials and with complex geometries, including geometries not possible to achieve with advanced mould-based techniques. We demonstrate r2rCLIP production of mouldable and non-mouldable shapes with voxel sizes as small as 2.0 × 2.0 µm2 in the print plane and 1.1 ± 0.3 µm unsupported thickness, at speeds of up to 1,000,000 particles per day. Such microscopic particles with permutable, intricate designs enable direct integration within biomedical, analytical and advanced materials applications.

A co-delivery system based on chlorin e6-loaded ROS-sensitive polymeric prodrug with self-amplified drug release to enhance the efficacy of combination therapy for breast tumor cells

Background: Recently, various combination therapies for tumors have garnered popularity because of their synergistic effects in improving therapeutic efficacy and reducing side effects. However, incomplete intracellular drug release and a single method of combining drugs are inadequate to achieve the desired therapeutic effect.

Methods: A reactive oxygen species (ROS)-sensitive co-delivery micelle (Ce6@PTP/DP). It was a photosensitizer and a ROS-sensitive paclitaxel (PTX) prodrug for synergistic chemo-photodynamic therapy. Micelles size and surface potential were measured. In vitro drug release, cytotoxicity and apoptosis were investigated.

Results: Ce6@PTP/DP prodrug micelles exhibited good colloidal stability and biocompatibility, high PTX and Ce6 loading contents of 21.7% and 7.38%, respectively. Upon light irradiation, Ce6@PTP/DP micelles endocytosed by tumor cells can generate sufficient ROS, not only leading to photodynamic therapy and the inhibition of tumor cell proliferation, but also triggering locoregional PTX release by cleaving the thioketal (TK) bridged bond between PTX and methoxyl poly (ethylene glycol). Furthermore, compared with single drug-loaded micelles, the light-triggered Ce6@PTP/DP micelles exhibited self-amplified drug release and significantly greater inhibition of HeLa cell growth.

Conclusion: The results support that PTX and Ce6 in Ce6@PTP/DP micelles exhibited synergistic effects on cell-growth inhibition. Thus, Ce6@PTP/DP micelles represent an alternative for realizing synergistic chemo-photodynamic therapy.

Static droplet array for the synthesis of nonspherical microparticles

We reported a manually operated static droplet array (SDA)-based device for the synthesis of nonspherical microparticles with different shapes. The improved SDA structure and reversible bonding between poly(dimethylsiloxane) (PDMS) were used in the device for the large-scale synthesis and rapid extraction of nonspherical microparticles. To understand the device physics, the effects of flow rate, SDA well size, and shape on droplet generation performances were explored. The results indicated that droplet generation in SDA structures was insensitive to the flow rate, and monodisperse droplets were generated by the SDA-based device through manually pushing the syringe. Finally, we integrated four kinds of SDA structures in one device and successfully realized the synthesis and extraction of nonspherical microparticles with different shapes and materials. Our SDA-based device offers numerous advantages, such as simple manual operation, low equipment cost, controllable microparticle shapes and sizes, and large-scale production. Thus, it holds the potential to be used as a flexible tool for the production of nonspherical microparticles.

Exploring Amodiaquine's Repurposing Potential in Breast Cancer Treatment-Assessment of In-Vitro Efficacy & Mechanism of Action

Due to the heterogeneity of breast cancer, current available treatment options are moderately effective at best. Hence, it is highly recommended to comprehend different subtypes, understand pathogenic mechanisms involved, and develop treatment modalities. The repurposing of an old FDA approved anti-malarial drug, amodiaquine (AQ) presents an outstanding opportunity to explore its efficacy in treating majority of breast cancer subtypes. Cytotoxicity, scratch assay, vasculogenic mimicry study, and clonogenic assay were employed to determine AQ's ability to inhibit cell viability, cell migration, vascular formation, and colony growth. 3D Spheroid cell culture studies were performed to identify tumor growth inhibition potential of AQ in MCF-7 and MDAMB-231 cell lines. Apoptosis assays, cell cycle analysis, RT-qPCR assays, and Western blot studies were performed to determine AQ's ability to induce apoptosis, cell cycle changes, gene expression changes, and induction of autophagy marker proteins. The results from in-vitro studies confirmed the potential of AQ as an anti-cancer drug. In different breast cancer cell lines tested, AQ significantly induces cytotoxicity, inhibit colony formation, inhibit cell migration, reduces 3D spheroid volume, induces apoptosis, blocks cell cycle progression, inhibit expression of cancer related genes, and induces LC3BII protein to inhibit autophagy. Our results demonstrate that amodiaquine is a promising drug to repurpose for breast cancer treatment, which needs numerous efforts from further studies.