Redox-Sensitive PEG–Polypeptide Nanoporous Particles for Survivin Silencing in Prostate Cancer Cells

Sorafenib/2800Z Co-Loaded into Cholesterol and PEG Grafted Polylysine NPs for Liver Cancer Treatment

The treatment of liver cancer remains challenging due to the low responsiveness of advanced cancer to therapeutic options. Sorafenib is the first line chemotherapeutic drug for advanced liver cancer but is frequently associated with severe side effects lead to discontinuation of chemotherapy. We previously developed a specific SIRT7 inhibitor 2800Z, which suppressed tumor growth and enhanced the chemosensitivity of sorafenib. In this study, we constructed polylysine polymer nanoparticles modified with cholesterol and GSH-sensitive PEG (mPssPC) to load sorafenib (SOR) and the SIRT7 inhibitor 2800Z to form dual-loaded NPs (S2@PsPCs) to reduce the toxicity and increase efficacy of sorafenib in liver cancer. The average size of S2@PsPC NPs was approximately 370 nm and the zeta potential was approximately 50-53 mV. We found that the release of the drugs exhibited pH sensitivity and was significantly accelerated in an acid release medium simulating the tumor environment. In addition, S2@PsPC NPs inhibited the proliferation and induced apoptosis of liver cancer cells in vitro. An in vivo study further revealed that S2@PsPCs showed high specificity to the liver cancer but low affinity and toxicity to the main organs including the heart, kidneys, lungs, and liver. Our data thus further approved the combination of a SIRT7 inhibitor and sorafenib for the treatment of liver cancer and provided new drug delivery system for targeted therapy.

Strategies for improving the safety and RNAi efficacy of noncovalent peptide/siRNA nanocomplexes

In the past decades, the striking development of cationic polypeptides and cell-penetrating peptides (CPPs) tailored for small interfering RNA (siRNA) delivery has been fuelled by the conception of nuclear acid therapy and precision medicine. Owing to their amino acid compositions, inherent secondary structures as well as diverse geometrical shapes, peptides or peptide-containing polymers exhibit good biodegradability, high flexibility, and bio-functional diversity as nonviral siRNA vectors. Also, a variety of noncovalent nanocomplexes could be built via self-assembling and electrostatic interactions between cationic peptides and siRNAs. Although the peptide/siRNA nanocomplex-based RNAi therapies, STP705 and MIR-19, are under clinical trials, a guideline addressing the current bottlenecks of peptide/siRNA nanocomplex delivery is in high demand for future research and development. In this review, we present strategies for improving the safety and RNAi efficacy of noncovalent peptide/siRNA nanocomplexes in the treatment of genetic disorders. Through thorough analysis of those RNAi formulations using different delivery strategies, we seek to shed light on the rationale of peptide design and modification in constructing robust siRNA delivery systems, including targeted and co-delivery systems. Based on this, we provide a timely and comprehensive understanding of how to engineer biocompatible and efficient peptide-based siRNA vectors.

Micro- and Nanocapsules Based on Artificial Peptides

The encapsulation of active ingredients into solid capsules from biodegradable materials has received significant attention over the last decades. In this short review, we focus on the formation of micro- and nano-sized capsules and emulsions based on artificial peptides as a fully degradable material. It deals with various approaches for the preparation of peptide-based capsules as well as with their crucial properties such as size and stability. We categorize all preparation procedures into three basic approaches: self-assembly, polymerization and crosslinking, and layer-by-layer technology. This article is meant to offer a short overview over all successful methods suitable for obtaining access to these very promising carrier systems.

Stimuli-responsive polypeptide nanoassemblies: Recent progress and applications in cancer nanomedicine

Stimuli-responsive polypeptide nanoassemblies exhibit great potentials for cancer nanomedicines because of desirable biocompatibility and biodegradability, unique secondary conformations, varying functionalities, and especially the stimuli-enhanced therapeutic efficacy and reduced side effect. This review introduces the design and fabrication of stimuli-responsive polypeptide nanoassemblies that exhibit endogenous stimuli (e.g., pH, reduction, reactive oxygen species, adenosine triphosphate and enzyme, etc.) and exogenous light stimuli (e.g., UV and near-infrared light), which are biologically related or applied in the clinic. We also discuss the applications and prospects of those stimuli-responsive polypeptide nanoassemblies that might overcome the biological barriers of cancer nanomedicines for in vivo administration. Much more effort is needed to accelerate the second-generation stimuli-responsive polypeptide nanomedicines for clinical transition and applications. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Poly(α-l-lysine)-based nanomaterials for versatile biomedical applications: Current advances and perspectives

Poly(α-l-lysine) (PLL) is a class of water-soluble, cationic biopolymer composed of α-l-lysine structural units. The previous decade witnessed tremendous progress in the synthesis and biomedical applications of PLL and its composites. PLL-based polymers and copolymers, till date, have been extensively explored in the contexts such as antibacterial agents, gene/drug/protein delivery systems, bio-sensing, bio-imaging, and tissue engineering. This review aims to summarize the recent advances in PLL-based nanomaterials in these biomedical fields over the last decade. The review first describes the synthesis of PLL and its derivatives, followed by the main text of their recent biomedical applications and translational studies. Finally, the challenges and perspectives of PLL-based nanomaterials in biomedical fields are addressed.

miRNAs as Therapeutic Tools and Biomarkers for Prostate Cancer

Prostate cancer (PCa) is the fifth cause of tumor-related deaths in man worldwide. Despite the considerable improvement in the clinical management of PCa, several limitations emerged both in the screening for early diagnosis and in the medical treatment. The use of prostate-specific antigen (PSA)-based screening resulted in patients’ overtreatment and the standard therapy of patients suffering from locally advanced/metastatic tumors (e.g., radical prostatectomy, radiotherapy, and androgen deprivation therapy) showed time-limited efficacy with patients undergoing progression toward the lethal metastatic castration-resistant PCa (mCRPC). Although valuable alternative therapeutic options have been recently proposed (e.g., docetaxel, cabazitaxel, abiraterone, enzalutamide, and sipuleucel-T), mCRPC remains incurable. Based on this background, there is an urgent need to identify new and more accurate prostate-specific biomarkers for PCa diagnosis and prognosis and to develop innovative medical approaches to counteract mCRPC. In this context, microRNA (miRNAs) emerged as potential biomarkers in prostate tissues and biological fluids and appeared to be promising therapeutic targets/tools for cancer therapy. Here we overview the recent literature and summarize the achievements of using miRNAs as biomarkers and therapeutic targets/tools for fighting PCa.

Polypeptide Nanoparticles with pH-Sheddable PEGylation for Improved Drug Delivery

The variation of tumor microenvironments provides a tool for the construction of stimulus-responsive nanomedicines to enhance drug delivery efficacy. Herein, the assembly of drug-loaded polypeptide nanoparticles (NPs) with pH-sheddable modification of poly(ethylene glycol) (PEG) is prepared to enhance therapeutic efficiency. Poly(l-lysine) and poly(l-glutamic acid) were self-assembled to fabricate polypeptide NPs by electrostatic interactions, followed by PEGylation based on amidation reaction. The NP sizes can be controlled by tuning the molecular weight or the ratio of polypeptides. The PEG coating is cleavable at the tumor acid microenvironment to reverse the surface charge and reduce the NP size, which effectively enhances cell uptake. In addition, the presence of reducing reagent (e.g., glutathione) in cancer cells induces the drug (i.e., cisplatin) release from the polypeptide NPs and subsequently results in the cell toxicity. This reported method highlights the engineering of transformable polypeptide drug carriers, which provides a promising way for enhanced drug delivery efficacy.

Polypeptide-Based Theranostics with Tumor-Microenvironment-Activatable Cascade Reaction for Chemo-ferroptosis Combination Therapy

Nanoengineering of polymer-based therapeutic carriers is promising for precise cancer treatment. Herein, we report the fabrication of polypeptide vehicles encapsulated with anticancer drug of cisplatin (Pt drug) and Fe₃O₄ nanoparticles (denoted as Pt&Fe₃O₄@PP) as theranostics for T₂-weighted magnetic resonance imaging (MRI)-guided chemo-ferroptosis combination therapy. The number of Fe₃O₄ nanoparticles per polypeptide vehicle is well controlled by adjusting the added amount of Fe₃O₄ nanoparticles. The tumor microenvironment can trigger the release of Pt drug and Fe^2/3+, which could induce the intracellular cascade reaction to generate sufficient ^•OH for ferroptosis therapy. Moreover, the released Pt drug can cause the apoptosis of tumor cells. Meanwhile, the encapsulated Fe₃O₄ nanoparticles can also be used for T₂-weighted MRI of tumor. Both in vitro and in vivo results indicate that the reported Pt&Fe₃O₄@PP can efficiently inhibit cancer cell growth without causing significant systemic toxicity. Importantly, polypeptide vehicles could significantly reduce the side effect of free Pt drug in vivo and therefore improve the drug delivery efficacy. Our findings suggest that polypeptide-based theranostics with tumor-microenvironment-activatable cascade reaction have great potential in biomedical applications.

Polymer Nanocontainers for Intracellular Delivery

Carriers for intracellular delivery are required to overcome limitations of therapeutic agents such as low specificity, systemic toxicity, high clearance rate, and low therapeutic index. Nanocontainers comprised of an aqueous core and a polymer shell have received increasing attention because they readily combine stimuli response to improve intracellular payload release and surface modification to enhance selectivity towards the desired region of action. This Minireview summarizes the design and properties of polymer nanocontainers for intracellular delivery, classified according to the polymer architecture.

Ultrasound-Responsive Materials for Drug/Gene Delivery

Ultrasound is one of the most commonly used methods in the diagnosis and therapy of diseases due to its safety, deep penetration into tissue, and non-invasive nature. In the drug/gene delivery systems, ultrasound shows many advantages in terms of site-specific delivery and spatial release control of drugs/genes and attracts increasing attention. Microbubbles are the most well-known ultrasound-responsive delivery materials. Recently, nanobubbles, droplets, micelles, and nanoliposomes have been developed as novel carriers in this field. Herein, we review advances of novel ultrasound-responsive materials (nanobubbles, droplets, micelles and nanoliposomes) and discuss the challenges of ultrasound-responsive materials in delivery systems to boost the development of ultrasound-responsive materials as delivery carriers.

Harnessing the Power of Optical Microscopic and Macroscopic Imaging for Natural Products as Cancer Therapeutics

Natural products (NPs) are an important source for new drug discovery over the past decades, which have been demonstrated to be effectively used in cancer prevention, treatment, and adjuvant therapy. Many methods, such as the genomic and metabolomic approaches, immunochemistry, mass spectrometry, and chromatography, have been used to study the effects of NPs on cancer as well as themselves. Because of the advantages in specificity, sensitivity, high throughput, and cost-effectiveness, optical imaging (OI) approaches, including optical microscopic imaging and macroscopic imaging techniques have also been applied in the studies of NPs. Optical microscopic imaging can observe NPs as cancer therapeutics at the cellular level and analyze its cytotoxicity and mechanism of action. Optical macroscopic imaging observes the distribution, metabolic pathway, and target lesions of NPs in vivo, and evaluates NPs as cancer therapeutics at the whole-body level in small living animals. This review focuses on the recent advances in NPs as cancer therapeutics, with particular emphasis on the powerful use of optical microscopic and macroscopic imaging techniques, including the studies of observation of ingestion by cells, anticancer mechanism, and in vivo delivery. Finally, we prospect the wider application and future potential of OI approaches in NPs as cancer therapeutics.

Redox-responsive polymer inhibits macrophages uptake for effective intracellular gene delivery and enhanced cancer therapy

The development of advanced gene delivery carriers with stimuli-responsive release manner for tumor therapeutics is desirable, since they can exclusively release the therapeutic gene via their structural changes in response to the specific stimuli of the target site. Moreover, interactions between macrophages and drug delivery systems (DDSs) seriously impair the treatment efficiency of DDSs, thus macrophages uptake inhibition would to some extent improve the intracellular uptake of DDSs in tumor cells. Herein, a PEGylated redox-responsive gene delivery system was developed for effective cancer therapy. PEG modified glycolipid-like polymer (P-CSSO) was electrostatic interacted with p53 to form P-CSSO/p53 complexes, which exhibited an enhanced redox sensitivity in that the disulfide bond was degraded and the rate the plasmid released from P-CSSO was 2.29-fold that of nonresponsive platform (P-CSO-SA) in 10 mM levels of glutathione (GSH). PEGylation could significantly weaken macrophages uptake, while enhance the accumulation of P-CSSO in tumor cells both in vitro and in vivo. Compared with nonresponsive complexes (P-CSO-SA/p53) (59.2%) and Lipofectamine™ 2000/p53 complexes (52.0%), the tumor inhibition rate of P-CSSO/p53 complexes (77.1%) significantly increased, which was higher than CSSO/p53 complexes (69.9%). The present study indicates that tumor microenvironment sensitive and macrophages uptake suppressive P-CSSO/p53 is a powerful in vivo gene delivery system for enhanced anticancer therapy.

[Effect of sodium phenylbutyrate on the sensitivity of PC3/DTX-resistant prostate cancer cells to docetaxel]

OBJECTIVE

To investigate the effect of sodium phenylbutyrate (SPB) in modulating docetaxel resistance in human prostate cancer cells in vitro.

METHODS

A PC3/docetaxel-resistant human prostate cancer cell line PC3/DTX was induced and examined for proliferation, viability, and cell inhibition rate in the presence of SPB. The concentration of concentration of docetaxel required to kill 50% of PC3/DTX cells incubated with 0, 1, 2, and 4 mmol/L SPB was determined using MTT assay. Cell apoptosis rate was analyzed with flow cytometry and the cellular expressions of p21, cyclin D1 and survivin proteins were detected using Western blotting.

RESULTS

Treatment of PC3/DTX cells with 0, 1, 2, and 4 mmol/L of SPB for 48 h resulted in cell viabilities of (99.85∓2.69)%, (84.68∓3.87)%, (68.65∓4.54)% and (43.54∓5.69)%, and cell inhibition rates of (10.69∓3.65)%, (25.78∓4.58)%, (54.68∓3.98)% and (69.84∓6.54)%, respectively (P<0.05). The concentration of docetaxel required to kill 50% of PC3/DTX cells cultured in the presence of with 0, 1, 2, and 4 mmol/L SPB was 135.98∓2.69, 109.65∓3.87, 87.65∓3.84 and 64.62∓2.98 nmol/L, respectively (P<0.05), and the cell apoptosis rates were (7.2∓0.8)%, (10.2∓0.9)%, (19.8∓2.1)% and (27.4∓2.5)%, respectively. SPB treatment promoted the protein expression of p21 and suppressed the expressions of cyclin D1 and survivin in PC3/DTX cells.

CONCLUSION

SPB can affect the expressions of p21, cyclin D1, and survivin in PC3/DTX cells and increase the sensitivity to the drug-resistant cells to docetaxel.

Preparation of photo-responsive poly(ethylene glycol) microparticles and their influence on cell viability

Intelligent colloidal particles have been widely used as carriers for delivery of bioactive molecules due to the ability of controlled release. However, attention is mainly paid to the effects of their payloads, whereas the impacts of carriers are largely ignored. In this study, photo-responsive polyethylene glycol (PEG) microparticles were fabricated by using 8-arm-PEG with terminal amine groups (8-arm-PEG-NH₂) and a photo-cleavable cross-linker. Due to the cleavable CO bond in the cross-linker, under UV irradiation the PEG particles could be decomposed gradually, leading to particle swelling and eventual disappearance. The PEG particles could be internalized by smooth muscle cells and HepG2 cells, and located in lysosomes. Their intracellular photo-response induced significant decrease of cell viability and increase of reactive oxygen species level.

Reduction-Responsive Polypeptide Micelles for Intracellular Delivery of Antineoplastic Agent

Reduction-responsive methoxy poly(ethylene glycol)-block-poly(S-tert-butylmercapto-L-cysteine) copolymers (i.e., mPEG₁₁₃-b-PBMLC₄ and mPEG₁₁₃-b-PBMLC₉) were facilely synthesized through primary amino-initiated ring-opening polymerization (ROP) of disulfide-containing N-carboxyanhydride monomer. The reduction-responsive block copolymers were then investigated for intracellular delivery of antitumor drug after forming smart micelles in vitro and in vivo. The micelles were denoted as P4M and P9M, respectively. Doxorubicin (DOX) was selected as a model chemotherapeutic agent, which was loaded into micelles via hydrophobic interaction. The drug loading efficiency (DLE) were detected to be 55.4 and 61.7 wt % for P4M and P9M, respectively. The loaded micelles, referred as P4M/DOX and P9M/DOX, exhibited spherical morphologies with hydrodynamic radii of 92.3 ± 2.3 and 80.2 ± 2.8 nm, respectively. Compared to P4M/DOX, P9M/DOX with a smaller size exhibited upregulated cell endocytosis and higher cytotoxicity to human breast cancer MCF-7 cells. Furthermore, the loading micelles, especially P9M/DOX, demonstrated improved antitumor efficacy toward an MCF-7 breast tumor-bearing BALB/c nude mouse model compared with free doxorubicin hydrochloride (DOX·HCl). This was also confirmed by the histopathological and immunohistochemical results. The above results demonstrated that the facially prepared smart polypeptide micelles exhibited a potent prospect in intracellular drug delivery in vitro and in vivo.

Highly efficient delivery of potent anticancer iminoquinone derivative by multilayer hydrogel cubes

We report a novel delivery platform for a highly potent anticancer drug, 7-(benzylamino)-3,4-dihydro-pyrrolo[4,3,2-de]quinolin-8(1H)-one (BA-TPQ), using pH- and redox-sensitive poly(methacrylic acid) (PMAA) hydrogel cubes of micrometer size as the encapsulating matrix. The hydrogels are obtained upon cross-linking PMAA with cystamine in PMAA/poly(N-vinylpyrrolidone) multilayers assembled within mesoporous sacrificial templates. The BA-TPQ-loaded hydrogels maintain their cubical shape and pH-sensitivity after lyophilization, which is advantageous for long-term storage. Conversely, the particles degrade in vitro in the presence of glutathione (5mM) providing 80% drug release within 24h. Encapsulating BA-TPQ into hydrogels significantly increases its transport via Caco-2 cell monolayers used as a model for oral delivery where the apparent permeability of BA-TPQ-hydrogel cubes was∼2-fold higher than that of BA-TPQ. BA-TPQ-hydrogel cubes exhibit better anticancer activity against HepG2 (IC50=0.52µg/mL) and Huh7 (IC50=0.29µg/mL) hepatoma cells with a 40% decrease in the IC50 compared to the non-encapsulated drug. Remarkably, non-malignant liver cells have a lower sensitivity to BA-TPQ-hydrogel cubes with 2-fold increased IC50 values compared to those of cancer cells. In addition, encapsulating BA-TPQ in the hydrogels amplifies the potency of the drug via down-regulation of MDM2 oncogenic protein and upregulation of p53 (a tumor suppressor) and p21 (cell proliferation suppressor) expression in HepG2 liver cancer cells. Moreover, enhanced inhibition of MDM2 protein expression by BA-TPQ-hydrogel cubes is independent of p53 status in Huh7 cells. This drug delivery platform of non-spherical shape provides a facile method for encapsulation of hydrophobic drugs and can facilitate the enhanced efficacy of BA-TPQ for liver cancer therapy.

STATEMENT OF SIGNIFICANCE

Many potent anticancer drugs are hydrophobic and lack tumor selectivity, which limits their application in cancer therapy. Although cubical hydrogels of poly(methacrylic acid) exhibit excellent biocompatibility and versatility, they have not been investigated for hydrophobic drug delivery due to poor mechanical stability and incompatibility between hydrophobic drugs and a hydrophilic hydrogel network. In this study, we provide a facile method to prepare a multilayer hydrogel-based platform with controlled nanostructure, cubical shape and redox-responsiveness for delivery of highly potent anticancer therapeutics, hydrophobic BA-TPQ. The BA-TPQ-hydrogel cubes have exceptional structural stability upon lyophilization which is advantageous for a long-term storage. The greatly enhanced trans-epithelial permeability and amplified anti-tumor activity of BA-TPQ are achieved by encapsulation in these hydrogel cubes. Furthermore, the anticancer BA-TPQ-hydrogel platform retains the selective activity of BA-TPQ to hepatocellular carcinoma cells. Overall, the produced BA-TPQ-hydrogel cubes demonstrate a high potential for clinical liver cancer therapy.

Injectable Supramolecular Hydrogels as Delivery Agents of Bcl-2 Conversion Gene for the Effective Shrinkage of Therapeutic Resistance Tumors

Injectable hydrogels to deliver therapeutic genes in a minimally invasive manner and to achieve long term sustained release at tumor sites to minimize side effects are attractive for cancer therapy and precision medicine, but its rational design remains a challenge. In this report, an injectable supramolecular hydrogel system is designed based on the polypesudorotaxane formation between α-cyclodextrin (α-CD) and cationic methoxy-poly(ethylene glycol)-b-poly(ε-caprolactone)-b-poly(ethylene imine) (MPEG-PCL-PEI) copolymer, with the ability to form polyplexes with anionic plasmid DNA for effective sustained gene delivery. To be mentioned, the MPEG-PCL-PEI copolymers show similar pDNA binding ability, better gene transfection efficiency, lower cytotoxicity than nonviral gene transfection gold standard PEI (25 kDa), due to the formation of micelles and more stable polyplexes. More importantly, this MPEG-PCL-PEI/α-CD/pDNA supramolecular hydrogel shows a sustained release of pDNA in form of polyplex for up to 7 d. By taking these advantages, this supramolecular hydrogel system is applied as an injectable carrier for sustained Bcl-2 conversion gene release, in an in vivo rodent model of therapeutic resistant hepatocarcinoma with high expression of antiapoptotic Bcl-2 protein. This work represents the first time that injectable MPEG-PCL-PEI/α-CD supramolecular hydrogels possess good controllable release effect of Bcl-2 conversion genes in the form of polyplex to effectively inhibit in vivo tumor growth and this "enemy to friend" strategy will benefit various applications, including on-demand gene delivery and personalized medicine.

Shaped stimuli-responsive hydrogel particles: syntheses, properties and biological responses

This review summarizes a pool of current experimental approaches and discusses perspectives in the development of the synergistic combination of shape and stimuli-response in particulate hydrogels.

Supramolecular cyclodextrin nanocarriers for chemo- and gene therapy towards the effective treatment of drug resistant cancers

A tumor active targeting β-cyclodextrin based nanocarrier β-NC-OEI-SS-FA was designed by the modification of star shaped cationic derivatives β-NC-OEI with folic acid through a disulfide bond, to co-deliver chemotherapeutic paclitaxel and the Nur77 gene for overcoming Bcl-2 mediated non-pump resistance by an "enemy to friend" strategy for potential drug resistant cancer therapy.

A combined approach for predicting the cytotoxic effect of drug-nanoaggregates

We present a combined spectroscopic and computational approach aimed to elucidate the mechanism of formation and activity of etoposide nanoaggregates upon release from dextran-etoposide conjugates. Etoposide is an anticancer drug that inhibits cell growth by blocking Topoisomerase II, the key enzyme involved in re-ligation of the DNA chains during the replication process. In silico and spectroscopic analysis indicate that released etoposide nanoaggregates have a different structure, stability, and bioactivity, which depend on the pH experienced during the release. Molecular dynamics simulation and in silico docking of etoposide dimers suggest that the aggregation phenomena inhibit etoposide bioactivity, yet without drastically preventing Topoisomerase II binding. We correlated the diminished cytotoxic activity exerted by dextran-etoposide conjugates on the A549 lung cancer cells, compared to the free drug, to the formation and stability of drug nanoaggregates.

Nanoengineered Templated Polymer Particles: Navigating the Biological Realm

Nanoengineered materials offer tremendous promise for developing the next generation of therapeutics. We are transitioning from simple research questions, such as "can this particle eradicate cancer cells?" to more sophisticated ones like "can we design a particle to preferentially deliver cargo to a specific cancer cell type?" These developments are poised to usher in a new era of nanoengineered drug delivery systems. We primarily work with templating methods for engineering polymer particles and investigate their biological interactions. Templates are scaffolds that facilitate the formation of particles with well-controlled size, shape, structure, stiffness, stability, and surface chemistry. In the past decade, breakthroughs in engineering new templates, combined with advances in coating techniques, including layer-by-layer (LbL) assembly, surface polymerization, and metal-phenolic network (MPN) coordination chemistry, have enabled particles with specific physicochemical properties to be engineered. While materials science offers an ever-growing number of new synthesis techniques, a central challenge of therapeutic delivery has become understanding how nanoengineered materials interact with biological systems. Increased collaboration between chemists, biologists, and clinicians has resulted in a vast research output on bio-nano interactions. Our understanding of cell-particle interactions has grown considerably, but conventional in vitro experimentation provides limited information, and understanding how to bridge the in vitro/in vivo gap is a continuing challenge. As has been demonstrated in other fields, there is now a growing interest in applying computational approaches to advance this area. A considerable knowledge base is now emerging, and with it comes new and exciting opportunities that are already being capitalized on through the translation of materials into the clinic. In this Account, we outline our perspectives gained from a decade of work at the interface between polymer particle engineering and bio-nano interactions. We divide our research into three areas: (i) biotrafficking, including cellular association, intracellular transport, and biodistribution; (ii) biodegradation and how to achieve controlled, responsive release of therapeutics; and (iii) applications, including drug delivery, controlling immunostimulatory responses, biosensing, and microreactors. There are common challenges in these areas for groups developing nanoengineered therapeutics. A key "lesson-learned" has been the considerable challenge of staying informed about the developments relevant to this field. There are a number of reasons for this, most notably the interdisciplinary nature of the work, the large numbers of researchers and research outputs, and the limited standardization in technique nomenclature. Additionally, a large body of work is being generated with limited central archiving, other than vast general databases. To help address these points, we have created a web-based tool to organize our past, present, and future work [Bio-nano research knowledgebase, http://bionano.eng.unimelb.edu.au/knowledge_base/ (accessed May 2, 2016)]. This tool is intended to serve as a first step toward organizing results in this large, complex area. We hope that this will inspire researchers, both in generating new ideas and also in collecting, collating, and sharing their experiences to guide future research.