Engineering biomimetic formulations for drug and gene delivery

Nanotechnology-based solutions have gained burgeoning attention in medical research, as compared with conventional therapeutic modalities, they offer advantages in efficacy, safety, and scalability. Researchers have been developing fluidic systems for nanoformulations over recent decades. Despite promising results, the clinical potential of the current nanosystems is still limited by insufficient cargo (drug and gene) loading, low production, high toxicity, low colloidal stability, unsatisfied bioavailability, and batch-to-batch variation. Flash-based self-assembly is a recently developed technology that can manufacture nanoformulations in facile, consistent, reproducible, and scalable manners. Due to the turbulent and dynamic flow generated in the mixing chamber, biomaterials self-assemble into uniform nanoparticles (NPs) through precipitation or complexation. We modified and manufactured a number of flash-based systems and evaluated their dynamic mixing profiles through simulation and empirical testing for polyplex formation and nanoparticle coating, as the dynamic fluidic control is the key for biomaterial complexation and nanoparticle coating, which provides better nanoparticle colloidal stability. In Chapter 2, we formulated polyplexes and lipid-coated NPs with controllable size and enhanced colloidal stability by exploiting the dynamic mixing of the flash-based system. Bio-inspired nanosystems with engineered functions have been advancing the field of nanomedicine. Incorporating bio-inspired components can provide nanosystems with productive ways of interacting with their surroundings by diminishing nonspecific interactions or enhancing specific targeting. Membranes from different cell types, and even organisms, can be employed and merged to meet specific goals. We derived cell membranes from distinctive mammalian cell lines to improve nanosystems with smart biological interactions, such as preserving neo-antigens or enhancing specific targeting. Another potent property of utilizing cell membranes is that they provide NPs with colloidal stability. Recent studies have reported the use of cell membrane coating onto NPs in drug delivery, imaging, phototherapies, and detoxification. The derived components from the original cell source bestow the NPs with their inherent functionality without additional complicated modulation. Cell membrane coating is a top-down technique that directly derives and harnesses the natural components, evading the technical and procedural challenges in bottom-up fabrication. However, current membrane coating techniques have problems of batch-to-batch variation and low production yield, which limits its potential for clinical translation. Taking advantage of flash-based self-assembly, we standardized and scaled up the cell membrane-coating process, which is difficult to achieve in bulk mixing approaches. The optimization of cell membrane coating was explored using various simulations. The time and cost for experimental design and optimization were reduced considerably. Cell membranes derived from tumor cells contain a rich source of tumor antigens. With the potential of cell membrane coating using flash-based self-assembly, we applied the produced cell-membrane-coated mesoporous silica nanoparticles (MSN) as a biomimetic nanovaccine for cancer immunotherapy in Chapter 3. Oral delivery of drugs and genes is a relatively convenient, patient-friendly, and safe approach. Targeted and controlled oral delivery of active pharmaceutical ingredients (API) of biomimetic nanocarriers offers significant advantages in efficacy and safety compared to conventional modalities. Besides mammalian cells, the unique functionalities of other prokaryotic and eukaryotic cell types, such as bacterium and yeasts, were exploited for macromolecule delivery. Baker’s yeast, a common yeast strain closely associated with food preparation, contains valuable polysaccharides that were reported to specifically bind to the dectin-1 receptors on the specialized intestinal epithelial cells and monocytes. Exploiting the yeast’s cell wall is a biomimetic strategy when designing an oral carrier for targeted oral drug and gene delivery. We demonstrated that the specific recognition between the microfold cells (M-cells) of the small intestine and the polysaccharides on the yeast cell wall enhances the transport of yeast-based formulations across the gut epithelium and into the lymphatic tissues in chapter 4. Utilizing the micron-sized yeast capsule or decorating a nanoparticle surface with processed yeast cell wall fragments, therapeutics were efficiently delivered to the target site through the oral path. The yeast-based formulations are biomimetic systems for targeted oral delivery of therapeutics. Taken together, the goal of this thesis is to close the gap between laboratory research and clinical translation by exploring the versatility and robustness of the developed flash technology, exploiting flash-based self-assembly for scalable production of the lipid and cell-membrane-coated nanosystems, and developing a relatively safe yeast-based drug and gene delivery platform

Applications of Nanobiomaterials in the Therapy and Imaging of Acute Liver Failure

Highlights This review focuses on the therapeutic mechanisms, targeting strategies of various nanomaterials in acute liver failure, and recent advances of diverse nanomaterials for acute liver failure therapy, diagnosis, and imaging. This review provides an outlook on the applications of nanomaterials, especially on the new horizons in acute liver failure therapy, and inspires broader interests across various disciplines. Acute liver failure (ALF), a fatal clinical disease featured with overwhelming hepatocyte necrosis, is a grand challenge in global health. However, a satisfactory therapeutic option for curing ALF is still absent, other than liver transplantation. Nanobiomaterials are currently being developed for the diagnosis and treatment of ALF. The liver can sequester most of nanoparticles from blood circulation, which becomes an intrinsic superiority for nanobiomaterials targeting hepatic diseases. Nanobiomaterials can enhance the bioavailability of free drugs, thereby significantly improving the therapeutic effects in ALF. Nanobiomaterials can also increase the liver accumulation of therapeutic agents and enable more effective targeting of the liver or specific liver cells. In addition, stimuli-responsive, optical, or magnetic nanomaterials exhibit great potential in the therapeutical, diagnostic, and imaging applications in ALF. Therefore, therapeutic agents in combination with nanobiomaterials increase the specificity of ALF therapy, diminish adverse systemic effects, and offer a multifunctional theranostic platform. Nanobiomaterial holds excellent significance and prospects in ALF theranostics. In this review, we summarize the therapeutic mechanisms and targeting strategies of various nanobiomaterials in ALF. We highlight recent developments of diverse nanomedicines for ALF therapy, diagnosis, and imaging. Furthermore, the challenges and future perspectives in the theranostics of ALF are also discussed

HSP27 Interacts with Nonstructural Proteins of Porcine Reproductive and Respiratory Syndrome Virus and Promotes Viral Replication

Heat shock protein 27 (HSP27) is a multifunctional protein and belongs to the small HSP family. It has been shown that HSP27 is involved in viral replication as a cellular chaperone, but the function of HSP27 during porcine reproductive and respiratory syndrome virus (PRRSV) infections remains unexplored. Here, we found that PRRSV replication can induce HSP27 expression and phosphorylation in vitro. HSP27 overexpression promoted PRRSV replication, whereas its knockdown reduced PRRSV proliferation. Additionally, suppressing HSP27 phosphorylation reduced PRRSV replication and the level of viral double-stranded RNA (dsRNA), a marker of the viral replication and transcription complexes (RTCs). Furthermore, HSP27 can interact with multiple viral nonstructural proteins (nsps), including nsp1α, nsp1β, nsp5, nsp9, nsp11 and nsp12. Suppressing the phosphorylation of HSP27 almost completely disrupted its interaction with nsp1β and nsp12. Altogether, our study revealed that HSP27 plays an important role in PRRSV replication

Shape Engineering Boosts Magnetic Mesoporous Silica Nanoparticle-Based Isolation and Detection of Circulating Tumor Cells

Magnetic mesoporous silica nanoparticles (M-MSNs) are attractive candidates for the immunomagnetic isolation and detection of circulating tumor cells (CTCs). Understanding of the interactions between the effects of the shape of M-MSNs and CTCs is crucial to maximize the binding capacity and capture efficiency as well as to facilitate the sensitivity and efficiency of detection. In this work, fluorescent M-MSNs were rationally designed with sphere and rod morphologies while retaining their robust fluorescence and uniform surface functionality. After conjugation with the antibody of epithelial cell adhesion molecule (EpCAM), both of the differently shaped M-MSNs-EpCAM obtained achieved efficient enrichment of CTCs and fluorescent-based detection. Importantly, rodlike M-MSNs exhibited faster immunomagnetic isolation as well as better performance in the isolation and detection of CTCs in spiked cells and real clinical blood samples than those of their spherelike counterparts. Our results showed that shape engineering contributes positively toward immunomagnetic isolation, which might open new avenues to the rational design of magnetic-fluorescent nanoprobes for the sensitive and efficient isolation and detection of CTCs

Genetic variants at 1q22 and 10q23 reproducibly associated with gastric cancer susceptibility in a Chinese population

Two recent genome-wide association studies reported significant associations of genetic variants at 1q22, 10q23 and 20p13 with gastric cancer (GC) risk in Chinese populations. However, these findings have not been confirmed in other independent studies. Here, we performed an independent case–control study in a Chinese population by genotyping three loci (rs4072037A>G at 1q22, rs2274223A>G at 10q23 and rs13042395C>T at 20p13) in 1681 GC cases and 1858 controls. We found that rs4072037 at 1q22 and rs2274223 at 10q23 were significantly associated with risk of GC with per allele odds ratio (OR) of 0.72 [95% confidence interval (CI): 0.63–0.81; P = 2.98 × 10−7] and 1.42 (95% CI: 1.27–1.58; P = 9.68 × 10−10), respectively. The association was more prominent for rs2274223 in female (OR = 1.86, 95% CI: 1.49–2.32) and gastric cardia adenocarcinoma (GCA) (OR = 1.71, 95% CI: 1.49–1.95). Furthermore, we combined the two single-nucleotide polymorphisms to evaluate the joint effect and found that the GC risk significantly increased with the number of risk allele increasing with a trend P value of 6.66 × 10−16, and individuals with four risk alleles had a 3.28-fold (95% CI: 1.75–6.13) risk of GC compared with those having no risk alleles. However, no significant association was detected between rs13042395 at 20p13 and GC risk (OR = 1.04, 95% CI: 0.94–1.15; P = 0.452). In conclusion, our results indicate that genetic variants at 1q22 and 10q23 but not 20p13 may serve as candidate markers for GC susceptibility in the Chinese population