Search

Figures S2, S3 and S4. Morphometric analysis of laminin-411 β1 chain (S2) and cancer stem cell markers (Notch-1, Notch-3, CD133, Nestin, and c-Myc; S3 and S4) on frozen sections of patient brain tumors. The expression of all markers significantly correlated with glioma grade

Video schematically shows the mechanism of glioblastoma treatment by laminin-411 inhibiting nanobioconjugate

Figure S5. Binding of the nanobioconjugates to U87MG studied by flow cytometry is inhibited by human soluble TfR. This shows that the chimeric anti-human TfR antibody as part of nanobioconjugate fully retained its activity

Figure S10. Expression of Notch-1 and its ligand Jagged1 is significantly decreased in patient-derived glioblastoma cell lines with laminin-411 disruption by CRISPR/Cas9

Figures S8 and S9. Quantification of expression of laminin-411 β1 chain, its binding β1 integrin, Notch family members and other stem cell markers after nanobioconjugate treatment. All markers were significantly suppressed in treated tumors.

Figures S6 and S7. Localization of labeled nanobioconjugates in tumors and biodistribution in brain. The nano drug is seen in the tumor parenchyma outside of blood vessels (S6) and preferentially accumulates in the tumor (peaks at 6 hr post-injection) as compared to contralateral brain tissue (S7)

Tables S1, S2 and S3, and Figure S1. List of used antibodies (Table S1), and immunohistochemical expression of laminin-411 and laminin-421 in human gliomas of various grades (Tables S2 and S3). Expression of laminin-411 vs. laminin-421 increases with glioma grade and in GBMs it correlates with shorter patient survival and faster tumor recurrence (Figure S1)

Table S4. Physico-chemical characterization of used control and treatment nanobioconjugates

The ability to cross the blood-brain barrier (BBB) is critical for targeted therapy of the central nerve system (CNS). Six peptide vectors were covalently attached to a 50 kDa poly(β-l-malic acid)-trileucine polymer forming P/LLL(40%)/vector conjugates. The vectors were Angiopep-2 (AP2), B6, Miniap-4 (M4), and d-configurated peptides D1, D3, and ACI-89, with specificity for transcytosis receptors low-density lipoprotein receptor-related protein-1 (LRP-1), transferrin receptor (TfR), bee venom-derived ion channel, and Aβ/LRP-1 related transcytosis complex, respectively. The BBB-permeation efficacies were substantially increased ("boosted") in vector conjugates of P/LLL(40%). We have found that the copolymer group binds at the endothelial membrane and, by an allosterically membrane rearrangement, exposes the sites for vector-receptor complex formation. The specificity of vectors is indicated by competition experiments with nonconjugated vectors. P/LLL(40%) does not function as an inhibitor, suggesting that the copolymer binding site is eliminated after binding of the vector-nanoconjugate. The two-step mechanism, binding to endothelial membrane and allosteric exposure of transcytosis receptors, is supposed to be an integral feature of nanoconjugate-transcytosis pathways.

Introduction: Tumor growth, invasion, and escape from immune surveillance largely depend on cancer microenvironment. Laminins are trimeric proteins and essential components of glioblastoma (GBM) microenvironment/extracellular matrix (ECM). In brain glioma samples from 230 patients, we found a correlation between the overexpression of tumor ECM protein laminin-411 (α4β1γ1) and faster tumor recurrence with shorter patient survival. Laminin-411 is produced by endothelial cells, neutrophils, monocytes, platelets, lymphocytes, and glioma cells and can modulate the immune system. Novel nanotechnology approach to block trimeric laminin-411 and activate of brain local immune system with brain delivery of PD-1 checkpoint inhibitor was developed for future translational application. Methods: Nanobioconjugates (NBC) based on poly (β-L-malic acid, P), were synthesized, characterized and used to intravenously treat mice with intracranial syngeneic GL261 or CT-2A GBM. The lead NBCs P/PEG/LLL(40%)/AON(α4β1)(2.0%)/AP-2(2%) and P/PEG/LLL(40%)/AP-2(2%)/αPD-1(0.2%) contained antisense to laminin-411 α4 and β1 chains, or αPD-1 antibody as well as trileucine (LLL) peptide for endosomal escape and AP-2 peptide for BBB crossing and tumor cell targeting. CRISPR/Cas9 constructs were used to knockdown α4 and β1 laminin chains in GBM ex vivo. Flow cytometry and RNA-seq analyses were performed to evaluate treatment. Results: Laminin-411 depletion with CRISPR/Cas9 and multifunctional NBC in vivo treatment equally suppressed GBM growth and significantly prolonged animal survival. The brain privileged immune system was activated upon treatment with a significant increase of CD3+, CD8+ T cells, NK, IFNγ+ NK cells, and M1 macrophages. RNA-sec analyses after treatment with a combination of NBC suppressing laminin-411 and checkpoint PD-1 showed enhanced anti-tumor effect with upregulation of genes coding for apoptotic Caspase 3 and IFNγ, and reduction of proliferation markers EGFR, c-Myc and Ki-67. Conclusion: Study describes novel GBM treatment strategy via NBCs crossing blood-brain barrier and targeting critical ECM and immune components of tumor microenvironment largely independent of heterogeneous genetic mutations in glioblastoma. Citation Format: Alexander V. Ljubimov, Rameshwar Patil, Hui Ding, Liron Israel, Eggehard Holler, Julia Y. Ljubimova, Tao Sun, Keith L. Black. Brain delivery of clinically suitable nanobioconjugates to inhibit glioblastoma growth through extracellular matrix-immune cell crosstalk [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 575.

Background Position of gadolinium atom(s) plays a key role in contrast enhancement of gadolinium-based contrast agents. To gain a better understanding of effects of distance of gadolinium in relation to the nanoconjugate platform, we designed and synthesized single- and multi-arm ("star") gadolinium conjugates equipped with antibody and peptides for targeting. The contrast agents were studied for their tumor imaging performance in a glioma mouse model. Materials and methods Antibody- and peptide-targeted nano contrast agents (NCAs) were synthesized using polymalic acid platforms of different sizes. Gadolinium-DOTA and intermediates were attached as amides and targeting agents such as antibodies and peptides as thioethers. For in vivo experiments, we used human U87MG xenografts as glioma models. Magnetic resonance imaging (MRI) was performed on a Bruker BioSpec 94/20USR 9.4 T small-animal scanner. Delivery of contrast agents across the blood-brain barrier was studied by fluorescent microscopy. Results All contrast agents accumulated into tumor and showed composition-dependent imaging performance. Peptide-targeted mini-NCAs had hydrodynamic diameters in the range 5.2-9.4 nm and antibody- targeted NCAs had diameters in the range 15.8-20.5 nm. Zeta potentials were in the range of -5.4--8.2 mV and -4.6--8.8 mV, respectively. NCAs showed superior relaxivities compared to MultiHance at 9.4 T. The signal enhancement indicated maximum accumulation in tumor 30-60 minutes after intravenous injection of the mouse tail vein. Only targeted NCAs were retained in tumor for up to 3 hours and displayed contrast enhancement. Conclusion The novel targeted NCAs with star-PEG features displayed improved relaxivity and greater contrast compared with commercial MultiHance contrast agent. The enhancement by mini-NCAs showed clearance of tumor contrast after 3 hours providing a suitable time window for tumor diagnosis in clinics. The technology provides a great tool with the promise of differential MRI diagnosis of brain tumors.

Differential diagnosis of brain magnetic resonance imaging (MRI) enhancement(s) remains a significant problem, which may be difficult to resolve without biopsy that can be often dangerous or even impossible. Such MRI enhancement(s) can result from metastasis of primary tumors such as lung or breast, radiation necrosis, infections or a new primary brain tumor (glioma, meningioma). Neurological symptoms are often the same on initial presentation. METHODS: We present a noninvasive tumor-specific imaging approach “MRI virtual biopsy” by engineering new nano imaging agents (NIA) on polymalic acid polymer (PMLA) scaffold containing linear-Gd-DOTA or star-Gd-DOTA moieties for differential diagnosis of brain tumors. The strategy is that after non-invasive MRI diagnosis recognizing the brain lesion on the basis of its molecular signatures, the primary cancer or brain metastasis (BM) is suppressed by tumor-specific molecular inhibitor(s), which is structurally similar to the used NIA. Anti-TfR antibody or Angiopep-2 (AP-2) peptide used to cross blood-brain barrier (BBB) by receptor-mediated transcytosis, and targeting antibody against EFGR- or HER2-overexpressing tumors were covalently attached to PMLA to recognize the tissues of interest. Delivery of contrast agents across BBB was studied by optical imaging. MRI signals in healthy brain and tumors were quantified using 9.4-Tesla MRI system. RESULTS: High specific signal values prevailed for 3 hours for NIA, in comparison with clinical Gd (MultiHance) that declined rapidly. In newly developed double tumor xenogeneic mouse models of brain metastasis this method allowed differential diagnosis of HER2- and EGFR-expressing brain tumors. After MRI diagnosis, breast and lung cancer brain metastases were successfully treated with similar tumor-targeted nanoconjugates carrying molecular inhibitors of EGFR or HER2 instead of imaging contrast agent. The treatment resulted in significant increase of animal survival and markedly reduced immunostaining for several cancer stem cell markers. Support: NIH grants: R01 CA188743, R01 CA206220, R01 CA209921

INTRODUCTION Lack of standard treatment of Primary Central Nervous System Lymphoma (PCNSL) was acknowledged in phase III intergroup study (HOVON 105/ALLG NHL 24). PCNSL incidence is increasing for unknown reasons, particularly among persons over 65 years. One of the major limitations of successful treatment of PCNSL is the blood-brain barrier (BBB), which prevents drug delivery into the brain. METHODS Polymer nanoconjugate based on biodegradable poly(N-(2-hydroxypropyl) methacrylamide) (PHPMA) was used for treatment of BALB/C mice with intracranially inoculated murine A20 lymphoma. PHPMA-based nanoconjugates have defined synthesis strategy for BBB transcytosis, tumor targeting, and cancer cell killing. Nano immunodrug PHPMA/AP-2/Fab’/c-Myc inhibitor/H6 conjugate contains multiple AP-2 peptides for efficient delivery across the BBB and Fab’ fragments of αCD20 mouse Ab for CD20 receptor crosslinking on PCNSL cells. c-Myc inhibitor bound via a disulfide bond is transferred to the cytoplasm followed by cleavage. The therapeutic efficacy and survival were evaluated together with spectral flow cytometry and RNA-seq bioinformatic analysis of tumor tissues. RESULTS Nanoconjugates were able to penetrate BBB and accumulate in brain parenchyma. The best survival results were obtained for the group where nanoconjugate with αCD20 Fab’ causing tumor cell apoptosis and c-Myc antisense inhibitor was combined with αPD-1 checkpoint inhibitor. Survival compared to PBS-treated controls was significant (P=0.0006 by ANOVA). Ex vivo analysis of A20 brain lymphoma tissue after treatment with nanoconjugates demonstrated reduction of Tregs, associated with downregulation of IL-10 and IL-1β in plasma. Spectral flow cytometry revealed activation of tumor infiltrating T lymphocytes and M1 macrophages in lead nanodrug treated groups. RNA-seq data correlated with flow cytometry results indicating the activation of genes linked to IFN-γ pathway important for anti-tumor response and M1 macrophage activation. Immunostaining confirmed a marked increase of M1-specific iNOS expression in the nanodrug-treated tumors. Support: NIH grants: R01 CA188743, R01 CA206220, R01 CA209921

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Research has increasingly focused on the delivery of high, often excessive amounts of drugs, neglecting negative aspects of the carrier’s physical preconditions and biocompatibility. Among them, little attention has been paid to “small but beautiful” design of vehicle and multiple cargo to achieve effortless targeted delivery into deep tissue. The design of small biopolymers for deep tissue targeted delivery of multiple imaging agents and therapeutics (mini-nano carriers) emphasizes linear flexible polymer platforms with a hydrodynamic diameter of 4 nm to 10 nm, geometrically favoring dynamic juxtaposition of ligands to host receptors, and economic drug content. Platforms of biodegradable, non-toxic poly(β-l-malic acid) of this size carrying multiple chemically bound, optionally nature-derived or synthetic affinity peptides and drugs for a variety of purposes are described in this review with specific examples. The size, shape, and multiple attachments to membrane sites accelerate vascular escape and fast blood clearance, as well as the increase in medical treatment and contrasts for tissue imaging. High affinity antibodies routinely considered for targeting, such as the brain through the blood–brain barrier (BBB), are replaced by moderate affinity binding peptides (vectors), which penetrate at high influxes not achievable by antibodies.

Glioblastoma (GBM) is the most prevalent primary brain cancer in the pediatric and adult population. It is known as an untreatable tumor in urgent need of new therapeutic approaches. The objective of this work was to develop multifunctional nanomedicines to treat GBM in clinical practice using combination therapy for several targets. We developed multifunctional nanopolymers (MNPs) based on a naturally derived biopolymer, poly(β-L-malic) acid, which are suitable for central nervous system (CNS) treatment. These MNPs contain several anticancer functional moieties with the capacity of crossing the blood–brain barrier (BBB), targeting GBM cells and suppressing two important molecular markers, tyrosine kinase transmembrane receptors EGFR/EGFRvIII and c-Myc nuclear transcription factor. The reproducible syntheses of MNPs where monoclonal antibodies are replaced with AP-2 peptide for effective BBB delivery were presented. The active anticancer inhibitors of mRNA/protein syntheses were Morpholino antisense oligonucleotides (AONs). Two ways of covalent AON-polymer attachments with and without disulfide bonds were explored. These MNPs bearing AONs to EGFR/EGFRvIII and c-Myc, as well as in a combination with the polymer-attached checkpoint inhibitor anti-PD-1 antibody, orchestrated a multi-pronged attack on intracranial mouse GBM to successfully block tumor growth and significantly increase survival of brain tumor-bearing animals.

Magnetic nanoparticles in general, and iron oxide nanoparticles in particular, have been studied extensively during the past 20 years for numerous biomedical applications. The main applications of these nanoparticles are in magnetic resonance imaging (MRI), magnetic targeting, gene and drug delivery, magnetic hyperthermia for tumor treatment, and manipulation of the immune system by macrophage polarization for cancer treatment. Recently, considerable attention has been paid to magnetic particle imaging (MPI) because of its better sensitivity compared to MRI. In recent years, MRI and MPI have been combined as a dual or multimodal imaging method to enhance the signal in the brain for the early detection and treatment of brain pathologies. Because magnetic and iron oxide nanoparticles are so diverse and can be used in multiple applications such as imaging or therapy, they have attractive features for brain delivery. However, the greatest limitations for the use of MRI/MPI for imaging and treatment are in brain delivery, with one of these limitations being the brain-blood barrier (BBB). This review addresses the current status, chemical compositions, advantages and disadvantages, toxicity and most importantly the future directions for the delivery of iron oxide based substances across the blood-brain barrier for targeting, imaging and therapy of primary and metastatic tumors of the brain.

Tumor environment in glioblastoma (GBM) is a dynamic interactive complex between tumor, immune and stem cells and extracellular matrix (ECM). In 226 patient glioma samples, we found a clinical correlation between expression of tumor vascular laminin-411 (α4β1γ1) and cancer stem cell (CSC) markers: Notch pathway members, CD133, Nestin, and c-Myc, with faster tumor recurrence and shorter survival of patients (Tao S, et al, Cancer Res., 2019). Novel nanotechnology approach to block trimeric ECM laminin-411 was developed for GBM treatment in experimental and preclinical models on human U87MG and LN229, and patient-derived TS543 and TS576 GBM cell lines. Nanobioconjugates (NBC) based on natural polymer, poly(β-L-malic acid), with antisense against laminin-411 α4 and β-chains, endosome escape unit (Ding H, et al, PNAS, USA, 2010), antibodies for blood-brain barrier (BBB) crossing and tumor targeting was characterized for toxicity and biodistribution according to FDA guidelines. Ex vivo depletion of laminin-411 α4 and β1 chains with CRISPR/Cas9 in human GBM cells led to reduced growth of intracranial tumors in mice, and significantly increased survival in hosts compared to mice with untreated cells. A nanobioconjugate potentially suitable for clinical use and capable of crossing BBB was designed to block laminin-411 expression. In biodistribution studies the NBC labeled with 125I on tyrosines of attached antibodies was accumulated in GBM but not in healthy brain tissue. Nanobioconjugate treatment of mice carrying intracranial GBM significantly increased animal survival and inhibited multiple CSC markers, Notch signaling system through the b1 integrin-Dll4 (Notch ligand) pathway. No toxicity revealed in 4 naïve Cynomolgus macaques after administration of three therapeutic 1X and acute 10X dosages of NBC. Conclusion: An efficient strategy of GBM treatment was developed via targeting a critical component of the tumor microenvironment, laminin-411, which is independent of heterogeneous genetic mutations in glioblastomas. Support: NIH grants U01CA151815, R01CA188743, R01CA206220, R01CA209921.

Maximal surgical resection of glioma remains the single most effective treatment. Tools to guide the resection while avoiding removal of normal brain tissues can aid surgeons in achieving optimal results. One strategy to achieve this goal is to rely upon interoperative fluorescence staining of tumor cells in vivo, that can be visualized by the surgeon during resection. Towards this goal we have designed a biodegradable fluorescent mini nano imaging agent (NIA) with high specificity for U87MG glioma cells and previously unmet high light emission. The NIA is the conjugate of polymalic acid (PMLA) with chlorotoxin for tumor targeting, indocyanine green (ICG) for NIR fluorescence and the tri-leucin peptide as fluorescence enhancer. PMLA as a multivalent platform carries several molecules of ICG and the other ligands. The NIA recognizes multiple sites on glioma cell surface, demonstrated by the effects of single and combined competitors. Systemic IV injection into xenogeneic mouse model carrying human U87MG glioblastoma indicated vivid tumor cell binding and internalization of NIA resulting in intensive and long-lasting tumor fluorescence. The NIA is shown to greatly improve tumor removal supporting its utility in clinical applications.

There is an unmet need for the treatment of glioblastoma multiforme (GBM). The extracellular matrix, including laminins, in the tumor microenvironment is important for tumor invasion and progression. In a panel of 226 patient brain glioma samples, we found a clinical correlation between the expression of tumor vascular laminin-411 (α4β1γ1) with higher tumor grade and with expression of cancer stem cell (CSC) markers, including Notch pathway members, CD133, Nestin, and c-Myc. Laminin-411 overexpression also correlated with higher recurrence rate and shorter survival of GBM patients. We also showed that depletion of laminin-411 α4 and β1 chains with CRISPR/Cas9 in human GBM cells led to reduced growth of resultant intracranial tumors in mice and significantly increased survival of host animals compared with mice with untreated cells. Inhibition of laminin-411 suppressed Notch pathway in normal and malignant human brain cell types. A nanobioconjugate potentially suitable for clinical use and capable of crossing blood–brain barrier was designed to block laminin-411 expression. Nanobioconjugate treatment of mice carrying intracranial GBM significantly increased animal survival and inhibited multiple CSC markers, including the Notch axis. This study describes an efficient strategy for GBM treatment via targeting a critical component of the tumor microenvironment largely independent of heterogeneous genetic mutations in glioblastoma. Significance: Laminin-411 expression in the glioma microenvironment correlates with Notch and other cancer stem cell markers and can be targeted by a novel, clinically translatable nanobioconjugate to inhibit glioma growth.

One of the major problems facing the treatment of neurological disorders is the poor delivery of therapeutic agents into the brain. Our goal is to develop a multifunctional and biodegradable nanodrug delivery system that crosses the blood—brain barrier (BBB) to access brain tissues affected by neurological disease. In this study, we synthesized a biodegradable nontoxic β-poly(L-malic acid) (PMLA or P) as a scaffold to chemically bind the BBB crossing peptides Angiopep-2 (AP2), MiniAp-4 (M4), and the transferrin receptor ligands cTfRL and B6. In addition, a trileucine endosome escape unit (LLL) and a fluorescent marker (rhodamine or rh) were attached to the PMLA backbone. The pharmacokinetics, BBB penetration, and biodistribution of nanoconjugates were studied in different brain regions and at multiple time points via optical imaging. The optimal nanoconjugate, P/LLL/AP2/rh, produced significant fluorescence in the parenchyma of cortical layers II/III, the midbrain colliculi, and the hippocampal CA1–3 cellular layers 30 min after a single intravenous injection; clearance was observed after 4 h. The nanoconjugate variant P/LLL/rh lacking AP2, or the variant P/AP2/rh lacking LLL, showed significantly less BBB penetration. The LLL moiety appeared to stabilize the nanoconjugate, while AP2 enhanced BBB penetration. Finally, nanoconjugates containing the peptides M4, cTfRL, and B6 displayed comparably little and/or inconsistent infiltration of brain parenchyma, likely due to reduced trans-BBB movement. P/LLL/AP2/rh can now be functionalized with intra-brain targeting and drug treatment moieties that are aimed at molecular pathways implicated in neurological disorders.

Human diabetic corneas develop delayed wound healing, epithelial stem cell dysfunction, recurrent erosions, and keratitis. Adenoviral gene therapy modulating c-Met, cathepsin F and MMP-10 normalized wound healing and epithelial stem cells in organ-cultured diabetic corneas but showed toxicity in stem cell-enriched cultured limbal epithelial cells (LECs). For a safer treatment, we engineered a novel nanobiopolymer (NBC) that carried antisense oligonucleotide (AON) RNA therapeutics suppressing cathepsin F or MMP-10, and miR-409-3p that inhibits c-Met. NBC was internalized by LECs through transferrin receptor (TfR)-mediated endocytosis, inhibited cathepsin F or MMP-10 and upregulated c-Met. Non-toxic NBC modulating c-Met and cathepsin F accelerated wound healing in diabetic LECs and organ-cultured corneas vs. control NBC. NBC treatment normalized levels of stem cell markers (keratins 15 and 17, ABCG2, and ΔNp63), and signaling mediators (p-EGFR, p-Akt and p-p38). Non-toxic nano RNA therapeutics thus present a safe alternative to viral gene therapy for normalizing diabetic corneal cells.

Purpose: Lack of standard treatment of Primary Central Nervous System Lymphoma (PCNSL) was acknowledged in phase III intergroup study (HOVON 105/ALLG NHL 24). PCNSL incidence is increasing for unknown reasons, particularly among persons over 65 years of age. The major limitation of successful treatment of PCNSL is the blood-brain barrier (BBB), which prevents drug delivery into the brain. Our novel treatment employs nano immunoconjugates (NICs) that cross BBB and activate brain lymphoma immunity. These NICs specifically block c-Myc expression and induce CD20 crosslinking. The NICs, in combination with αPD1, were systemically delivered to the lymphoma mice and this treatment led to a local and systemic broad-spectrum immune response by activation of IFN-γ that is an important anti-tumor M1 macrophage activator. Methods: Polymer nanoconjugate based on biodegradable poly(N-(2-hydroxypropyl) methacrylamide) (PHPMA)-P was used for treatment of BALB/C mice with intracranially inoculated murine A20 lymphoma. PHPMA-based nanoconjugates have defined synthesis strategy for BBB transcytosis, tumor targeting, and cancer cell killing. Nano-immunodrug P/AP-2/CD20 Fab'or c-Myc inhibitor (anti-sense oligonucleotides)/H6 conjugate contains multiple AP-2 peptides for efficient delivery across the BBB and Fab' fragments of αCD20 Ab (mouse specific) for CD20 receptor crosslinking on PCNSL cells. c-Myc inhibitor bound via a disulfide bond is transferred to the cytoplasm followed by cleavage; this is facilitated by (His)6 peptide-mediated endosome disruption. The nanoconjugate was examined for the ability to cross BBB in vivo by live imaging. The therapeutic efficacy and survival were evaluated together with spectral flow cytometry (FC) and RNA-seq bioinformatic analysis of tumor tissues. Results: NIC was able to penetrate BBB and accumulate in brain parenchyma. The best survival results were obtained from the combination groups with CD20 Fab' crosslinking CD20 receptors resulting in apoptosis and c-Myc antisense inhibition in combination with αPD-1 checkpoint inhibitor. Survival compared to PBS-treated controls was significant (P=0.0006, P=0.0034, respectively, by ANOVA). FC analysis of A20 brain lymphoma tissue after treatment with NICs demonstrated reduction of Tregs, associated with downregulation of IL-10 and IL-1β in plasma. Spectral flow cytometry revealed activation of tumor infiltrating T lymphocytes and the M1 macrophages in lead treatment groups. RNA-seq data correlated with flow cytometry results indicating the activation of genes linked to IFN-γ pathway important for anti-tumor response and M1 macrophage activation. Immunostaining confirmed a marked increase of M1-specific iNOS expression in the nanodrug-treated tumors. Conclusion: The PCNSL treatment results demonstrate for the first time that the BBB delivery of NICs modified brain tumor microenvironment and activated brain local immune system though modulation of T cells and IFN-γ pathway. Support: NIH grants: R01 CA188743, R01 CA206220, R01 CA209921 Citation Format: Tao Sun, Ekaterina Shatalova, Oliver Braubach, Dmytro Klymyshyn, Eggehard Holler, Jiawei Wang, Lian Li, Jiyuan Yang, Jindrich Kopecek, Julia Y. Ljubimova. Nano-immuno combination therapy to treat brain primary central nervous system lymphoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2869.

Treatment of brain gliomas with checkpoint inhibitor antibodies to cytotoxic T-lymphocyte-associated antigen 4 (a-CTLA-4) and programmed cell death-1 (a-PD-1) was largely unsuccessful due to their inability to cross the blood-brain barrier (BBB). We describe a new generation of nano immunoconjugates (NICs) developed on natural biopolymer scaffold, poly(β-L-malic acid), with covalently attached a-CTLA-4 and/or a-PD-1 for delivery across the BBB and activation of local brain anti-tumor immune response in glioma-bearing mice. NIC treatment of mice bearing intracranial GL261 glioblastoma (GBM) resulted in an increase of CD8+ T-cells with a decrease of T regulatory cells (Tregs) in the brain tumor area. Survival of GBM-bearing mice treated with combination of NICs was significantly longer compared to animals treated by single checkpoint inhibitor-bearing NICs or free a-CTLA-4 and a-PD-1. Our study demonstrates trans-BBB delivery of nanopolymer-conjugated checkpoint inhibitors as an effective treatment of GBM via activation of both systemic and local brain tumor immune response.

Air pollution is linked to brain inflammation, which accelerates tumorigenesis and neurodegeneration. The molecular mechanisms that connect air pollution with brain pathology are largely unknown but seem to depend on the chemical composition of airborne particulate matter (PM). We sourced ambient PM from Riverside, California, and selectively exposed rats to coarse (PM2.5–10: 2.5–10 µm), fine (PM: 2.5–10 exposures triggered the expression of the early growth response gene 2 (EGR2), genes encoding inflammatory cytokine pathways (IL13-Rα1 and IL-16) and the oncogene RAC1. Gene upregulation occurred only in brains of rats exposed to PM2.5–10 and correlated with cerebral nickel accumulation. We hypothesize that the expression of inflammation and oncogenesis-related genes is triggered by the combinatorial exposure to certain metals and toxins in Los Angeles Basin PM2.5–10.

Professor Black and colleagues have been working to improve thequality and sensitivity of imaging in the early detection of conditionsfrom brain tumors to Alzheimer’s disease to enhance treatment protocolsand patient management. Professor Black et al introduced nanoparticlesto improve MRI imaging. These nanoparticles consist of poly(b-L- malic acid (PMLA)) conjugates with monoclonal antibodies((mAbs)) and Gd-DOTA. These are known as MRI nano-imagingagents (NIA). Most importantly, they can penetrate the endothelialblood-brain barrier (BBB) to reach brain tumors (primary or metastasis).This is effective in cases of brain tumors or breast cancer orother cancers such as lung cancer and gastric cancer having HER2and/or EGFR positive crossing BBB. By the covalent conjugation ofMR contrast (NIA), the MRI virtual biopsy can differentiate braintumors from infections or other brain pathological conditions. Thebrain’s intrinsic natural fl uorescence such as NADH, FAD, lipopigmentsand porphyrin in the brain tissue can be identifi ed by using timeresolved fl uorescence spectroscopy (TRFS) which is operated throughthe use of ultra-short laser. TRFS produces various color bands todifferentiate the tumor from normal brain tissue in real time andregisters the data on a 3D map. This is signifi cant, as this will provide agreatly improved assessment methodology of tissue type. Consequently,this will potentially result in shorter operation times as well as moresatisfactory tumor removal. In the detection of Alzheimer disease,amyloid plaque is deposited in retina tissue (including the RGC, RNFLand inner plexiform layer) which can produce a fl uorescence effectby using curcumin as a contrast. This is then shown by human retinaamyloid imaging device. Immunotherapies with glatiramer acetate(GA) have been shown to reduce amyloid deposits in brain andretinal AB deposits in mice. The study of advanced imagingtechnology and techniques including NIA, TRFS and the detection ofamyloid plaque in Alzheimer disease are very important approaches tocreate a new era for diagnostic and therapeutic management of braintumors and other cancers (HER2 and/or EGFR positive). This pioneeringwork by Professor Black, and colleagues, gives rise to a new hopefor cancer patients for targeted therapy and for immunotherapies inAlzheimer’s disease.

Currently, there is no gadolinium-based contrast agent available for conventional magnetic resonance imaging (MRI) detection of amyloidal beta (Aβ) plaques in Alzheimer's disease (AD). Its timely finding would be vital for patient survival and quality of life. Curcumin (CUR), a common Indian spice effectively binds to Aβ plaques which is a hallmark of AD. To address this binding, we have designed a novel nanoimaging agent (NIA) based on nature-derived poly(β-l-malic acid) (PMLA) containing covalently attached gadolinium-DOTA(Gd-DOTA) and nature-derived CUR. The all-in-one agent recognizes and selectively binds to Aβ plaques and is detected by MRI. It efficiently detected Aβ plaques in human and mouse samples by an ex vivo staining. The method can be useful in clinic for safe and noninvasive diagnosis of AD.

Differential diagnosis of brain magnetic resonance imaging (MRI) enhancement(s) remains a significant problem, which may be difficult to resolve without biopsy, which can be often dangerous or even impossible. Such MRI enhancement(s) can result from metastasis of primary tumors such as lung or breast, radiation necrosis, infections, or a new primary brain tumor (glioma, meningioma). Neurological symptoms are often the same on initial presentation. To develop a more precise noninvasive MRI diagnostic method, we have engineered a new class of poly(β-L-malic acid) polymeric nanoimaging agents (NIAs). The NIAs carrying attached MRI tracer are able to pass through the blood–brain barrier (BBB) and specifically target cancer cells for efficient imaging. A qualitative/quantitative “MRI virtual biopsy” method is based on a nanoconjugate carrying MRI contrast agent gadolinium-DOTA and antibodies recognizing tumor-specific markers and extravasating through the BBB. In newly developed double tumor xenogeneic mouse models of brain metastasis this noninvasive method allowed differential diagnosis of HER2- and EGFR-expressing brain tumors. After MRI diagnosis, breast and lung cancer brain metastases were successfully treated with similar tumor-targeted nanoconjugates carrying molecular inhibitors of EGFR or HER2 instead of imaging contrast agent. The treatment resulted in a significant increase in animal survival and markedly reduced immunostaining for several cancer stem cell markers. Novel NIAs could be useful for brain diagnostic MRI in the clinic without currently performed brain biopsies. This technology shows promise for differential MRI diagnosis and treatment of brain metastases and other pathologies when biopsies are difficult to perform.

Multifunctional polymer nanoconjugates containing multiple components show great promise in cancer therapy, but in most cases complete analysis of each component is difficult. Polymalic acid (PMLA) based nanoconjugates have demonstrated successful brain and breast cancer treatment. They consist of multiple components including targeting antibodies, Morpholino antisense oligonucleotides (AONs), and endosome escape moieties. The component analysis of PMLA nanoconjugates is extremely difficult using conventional spectrometry and HPLC method. Taking advantage of the nature of polyester of PMLA, which can be cleaved by ammonium hydroxide, we describe a method to analyze the content of antibody and AON within nanoconjugates simultaneously using SEC-HPLC by selectively cleaving the PMLA backbone. The selected cleavage conditions only degrade PMLA without affecting the integrity and biological activity of the antibody. Although the amount of antibody could also be determined using the bicinchoninic acid (BCA) method, our selective cleavage method gives more reliable results and is more powerful. Our approach provides a new direction for the component analysis of polymer nanoconjugates and nanoparticles.

Uncontrolled bleeding and infection are the major causes of death and morbidity from traumatic wounds during military conflicts, disasters, and accidents. Because immediate treatment is critical to survival, it is desirable to have a lightweight and rapidly applicable bandage—one capable of delivering a hemostat that can quickly resolve bleeding while addressing infection over short and longer time frames. It is challenging to design thin film coatings capable of multidrug release, particularly when the drugs are quite different in nature (biologic versus small molecule, charged versus neutral) and the desired release profiles are different for each drug. Herein we have adopted a layer-by-layer film assembly technique to create a linear combination of two independently functional films capable of rapidly releasing thrombin within minutes while sustaining vancomycin elution for more than 24 h. By conjugating vancomycin to a hydrolytically degradable polyacid, poly(β-L-malic acid), we were able to create a robust thin film with loading and release kinetics that remain unaffected by the additional deposition of a thrombin-based film, demonstrating the possibility for future multitherapeutic films with independently tunable release kinetics.

Air pollution is linked to brain inflammation, which accelerates tumorigenesis and neurodegeneration. The molecular mechanisms that connect air pollution with brain pathology are largely unknown but seem to depend on the chemical composition of airborne particulate matter (PM). We sourced ambient PM from Riverside, California, and selectively exposed rats to coarse (PM2.5–10: 2.5–10 µm), fine (PM

Professor Black and colleagues have been working to improve the quality and sensitivity of imaging in the early detection of conditions from brain tumors to Alzheimer’s disease to enhance treatment protocols and patient management. Professor Black et al introduced nanoparticles to improve MRI imaging. These nanoparticles consist of poly (b-L- malic acid (PMLA)) conjugates with monoclonal antibodies ((mAbs)) and Gd-DOTA. These are known as MRI nano-imaging agents (NIA). Most importantly, they can penetrate the endothelial blood-brain barrier (BBB) to reach brain tumors (primary or metastasis). This is effective in cases of brain tumors or breast cancer or other cancers such as lung cancer and gastric cancer having HER2 and/or EGFR positive crossing BBB. By the covalent conjugation of MR contrast (NIA), the MRI virtual biopsy can differentiate brain tumors from infections or other brain pathological conditions. The brain’s intrinsic natural fluorescence such as NADH, FAD, lipopigments and porphyrin in the brain tissue can be identified by using time resolved fluorescence spectroscopy (TRFS) which is operated through the use of ultra-short laser. TRFS produces various color bands to differentiate the tumor from normal brain tissue in real time and registers the data on a 3D map. This is significant, as this will provide a greatly improved assessment methodology of tissue type. Consequently, this will potentially result in shorter operation times as well as more satisfactory tumor removal. In the detection of Alzheimer disease, amyloid plaque is deposited in retina tissue (including the RGC, RNFL and inner plexiform layer) which can produce a fluorescence effect by using curcumin as a contrast. This is then shown by human retina amyloid imaging device. Immunotherapies with glatiramer acetate (GA) have been shown to reduce amyloid deposits in brain and retinal AB deposits in mice. The study of advanced imaging technology and techniques including NIA, TRFS and the detection of amyloid plaque in Alzheimer disease are very important approaches to create a new era for diagnostic and therapeutic management of brain tumors and other cancers (HER2 and/or EGFR positive). This pioneering work by Professor Black, and colleagues, gives rise to a new hope for cancer patients for targeted therapy and for immunotherapies in Alzheimer’s disease.

Nanomedicine is a rapidly evolving form of therapy that holds a great promise for superior drug delivery efficiency and therapeutic efficacy than conventional cancer treatment. In this review, we attempt to cover the benefits and the limitations of current nanomedicines with special attention to covalent nano conjugates for imaging and drug delivery in the brain. The improvement in brain tumor treatment remains dismal despite decades of efforts in drug development and patient care. One of the major obstacles in brain cancer treatment is the poor drug delivery efficiency owing to the unique blood-brain barrier (BBB) in the CNS. Although various anti-cancer agents are available to treat tumors outside of the CNS, the majority fails to cross the BBB. In this regard, nanomedicines have increasingly drawn attention due to their multi-functionality and versatility. Nano drugs can penetrate BBB and other biological barriers, and selectively accumulate in tumor cells, while concurrently decreasing systemic toxicity.

Anionic polymers with membrane permeation functionalities are highly desirable for secure cytoplasmic drug delivery. We have developed tritryptophan containing copolymer (P/WWW) of polymalic acid (PMLA) that permeates membranes by a mechanism different from previously described PMLA copolymers of trileucine (P/LLL) and leucine ethyl ester (P/LOEt) that use the “barrel stave” and “carpet” mechanism, respectively. The novel mechanism leads to solubilization of membranes by forming copolymer “belts” around planar membrane “packages.” The formation of such packages is supported by results obtained from studies including size-exclusion chromatography, confocal microscopy, and fluorescence energy transfer. According to this “belt” mechanism, it is hypothesized that P/WWW first attaches to the membrane surface. Subsequently the hydrophobic tryptophan side chains translocate into the periphery and insert into the lipid bilayer thereby cutting the membrane into packages. The reaction is driven by the high affinity between the tryptophan residues and lipid side chains resulting in a stable configuration. The formation of the membrane packages requires physical agitation suggesting that the success of the translocation depends on the fluidity of the membrane. It is emphasized that the “belt” mechanism could specifically function in the recognition of abnormal cells with high membrane fluidity and in response to hyperthermia.

Multidrug regimens can sometimes treat recalcitrant diseases when single-drug therapies fail. Recapitulating complex multidrug administration from controlled release films for localized delivery remains challenging because their release kinetics are frequently intertwined, and an initial burst release of each drug is usually uncontrollable. Kinetic control over protein release is demonstrated by cross-linking layer-by-layer films during the assembly process. We used biodegradable and naturally derived components and relied on copper-free click chemistry for bioorthogonal covalent cross-links throughout the film that entrap but do not modify the embedded protein. We found that this strategy restricted the interdiffusion of protein while maintaining its activity. By depositing a barrier layer and a second protein-containing layer atop this construct, we generated well-defined sequential protein release with minimal overlap that follows their spatial distribution within the film., United States. Army Research Office (Contract W911NF-13-D-0001), United States. Air Force (Contract W911NF-07-D-0004)

Esterification of microbial poly(malic acid) is performed with either ethanol or 1-butanol to obtain polymalate conjugates capable to form nanoparticles (100–350 nm). Degradation under physiological conditions takes place with release of malic acid and the corresponding alcohol as unique degradation products. The anticancer drugs Temozolomide and Doxorubicin are encapsulated in nanoparticles with efficiency of 17 and 37%, respectively. In vitro drug release assays show that Temozolomide is almost completely discharged in a few hours whereas Doxorubicin is steadily released along several days. Drug-loaded nano-particles show remarkable effectiveness against cancer cells. Partially ethylated poly(malic acid) nano-particles are those showing the highest cellular uptake.

Herein we designed and characterized films composed of naturally derived materials for controlled release of proteins. Traditional drug delivery strategies rely on synthetic or semi-synthetic materials, or utilize potentially denaturing assembly conditions that are not optimal for sensitive biologics. Layer-by-Layer (LbL) assembly of films uses benign conditions and can generate films with various release mechanisms including hydrolysis-facilitated degradation. These use components such as synthetic polycations that degrade into non-natural products. Herein we report the use of a naturally-derived, biocompatible and degradable polyanion, poly(β-l-malic acid), alone and in combination with chitosan in an LbL film, whose degradation products of malic acid and chitosan are both generally recognized as safe (GRAS) by the FDA. We have found that films based on this polyanion have shown sustained release of a model protein, lysozyme that can be timed from tens of minutes to multiple days through different film architectures. We also report the incorporation and release of a clinically used biologic, basic fibroblast growth factor (bFGF), which demonstrates the use of this strategy as a platform for controlled release of various biologics.