In vitro and in ovo photodynamic efficacy of nebulized curcumin-loaded tetraether lipid liposomes prepared by DC as stable drug delivery system.

Lung cancer is one of the most common causes of high mortality worldwide. Current treatment strategies, e.g., surgery, radiotherapy, chemotherapy, and immunotherapy, insufficiently affect the overall outcome. In this study, we used curcumin as a natural photosensitizer in photodynamic therapy and encapsulated it in liposomes consisting of stabilizing tetraether lipids aiming for a pulmonary drug delivery system against lung cancer. The liposomes with either hydrolyzed glycerol-dialkyl-glycerol tetraether (hGDGT) in different ratios or hydrolyzed glycerol-dialkyl-nonitol tetraether (hGDNT) were prepared by dual centrifugation (DC), an innovative method for liposome preparation. The liposomes' physicochemical characteristics before and after nebulization and other nebulization characteristics confirmed their suitability. Morphological characterization using atomic force and transmission electron microscopy showed proper vesicular structures indicative of liposomes. Qualitative and quantitative uptake of the curcumin-loaded liposomes in lung adenocarcinoma (A549) cells was visualized and proven. Phototoxic effects of the liposomes were detected on A549 cells, showing decreased cell viability. The generation of reactive oxygen species required for PDT and disruption of mitochondrial membrane potential were confirmed. Moreover, the chorioallantoic membrane (CAM) model was used to further evaluate biocompatibility and photodynamic efficacy in a 3D cell culture context. Photodynamic efficacy was assessed by PET/CT after nebulization of the liposomes onto the xenografted tumors on the CAM with subsequent irradiation. The physicochemical properties and the efficacy of tetraether lipid liposomes encapsulating curcumin, especially liposomes containing hGDNT, in 2D and 3D cell cultures seem promising for future PDT usage against lung cancer.

Evaluating the photodynamic efficacy of nebulized curcumin-loaded liposomes prepared by thin-film hydration and dual centrifugation: In vitro and in ovo studies.

Lung cancer, one of the most common causes of high mortality worldwide, still lacks appropriate and convenient treatment options. Photodynamic therapy (PDT) has shown promising results against cancer, especially in recent years. However, pulmonary drug delivery of the predominantly hydrophobic photosensitizers still represents a significant obstacle. Nebulizing DPPC/Cholesterol liposomes loaded with the photosensitizer curcumin via a vibrating mesh nebulizer might overcome current restrictions. In this study, the liposomes were prepared by conventional thin-film hydration and two other methods based on dual centrifugation. The liposomes' physicochemical properties were determined before and after nebulization, showing that liposomes do not undergo any changes. However, morphological characterization of the differently prepared liposomes revealed structural differences between the methods in terms of lamellarity. Internalization of curcumin in lung adenocarcinoma (A549) cells was visualized and quantified. The generation of reactive oxygen species because of the photoreaction was also proven. The photodynamic efficacy of the liposomal formulations was tested against A549 cells. They revealed different phototoxic responses at different radiant exposures. Furthermore, the photodynamic efficacy was investigated after nebulizing curcumin-loaded liposomes onto xenografted tumors on the CAM, followed by irradiation, and evaluated using positron emission tomography/computed tomography and histological analysis. A decrease in tumor metabolism could be observed. Based on the efficacy of curcumin-loaded liposomes in 2D and 3D models, liposomes, especially with prior film formation, can be considered a promising approach for PDT against lung cancer.

Modern Photodynamic Glioblastoma Therapy Using Curcumin- or Parietin-Loaded Lipid Nanoparticles in a CAM Model Study.

Natural photosensitizers, such as curcumin or parietin, play a vital role in photodynamic therapy (PDT), causing a light-mediated reaction that kills cancer cells. PDT is a promising treatment option for glioblastoma, especially when combined with nanoscale drug delivery systems. The curcumin- or parietin-loaded lipid nanoparticles were prepared via dual asymmetric centrifugation and subsequently characterized through physicochemical analyses including dynamic light scattering, laser Doppler velocimetry, and atomic force microscopy. The combination of PDT and lipid nanoparticles has been evaluated in vitro regarding uptake, safety, and efficacy. The extensive and well-vascularized chorioallantois membrane (CAM) of fertilized hen's eggs offers an optimal platform for three-dimensional cell culture, which has been used in this study to evaluate the photodynamic efficacy of lipid nanoparticles against glioblastoma cells. In contrast to other animal models, the CAM model lacks a mature immune system in an early stage, facilitating the growth of xenografts without rejection. Treatment of xenografted U87 glioblastoma cells on CAM was performed to assess the effects on tumor viability, growth, and angiogenesis. The xenografts and the surrounding blood vessels were targeted through topical application, and the effects of photodynamic therapy have been confirmed microscopically and via positron emission tomography and X-ray computed tomography. Finally, the excised xenografts embedded in the CAM were analyzed histologically by hematoxylin and eosin and KI67 staining.

Predictive Factors Associated with Declining Psycho-Oncological Support in Patients with Cancer.

(1) Background: International cancer treatment guidelines recommend low-threshold psycho-oncological support based on nurses' routine distress screening (e.g., via the distress thermometer and problem list). This study aims to explore factors which are associated with declining psycho-oncological support in order to increase nurses' efficiency in screening patients for psycho-oncological support needs. (2) Methods: Using machine learning, routinely recorded clinical data from 4064 patients was analyzed for predictors of patients declining psycho-oncological support. Cross validation and nested resampling were used to guard against model overfitting. (3) Results: The developed model detects patients who decline psycho-oncological support with a sensitivity of 89% (area under the cure of 79%, accuracy of 68.5%). Overall, older patients, patients with a lower score on the distress thermometer, fewer comorbidities, few physical problems, and those who do not feel sad, afraid, or worried refused psycho-oncological support. (4) Conclusions: Thus, current screening procedures seem worthy to be part of daily nursing routines in oncology, but nurses may need more time and training to rule out misconceptions of patients on psycho-oncological support.

Photoactive Parietin-loaded nanocarriers as an efficient therapeutic platform against triple-negative breast cancer.

The application of photodynamic therapy has become more and more important in combating cancer. However, the high lipophilic nature of most photosensitizers limits their parenteral administration and leads to aggregation in the biological environment. To resolve this problem and deliver a photoactive form, the natural photosensitizer parietin (PTN) was encapsulated in poly(lactic-co-glycolic acid) nanoparticles (PTN NPs) by emulsification diffusion method. PTN NPs displayed a size of 193.70 nm and 157.31 nm, characterized by dynamic light scattering and atomic force microscopy, respectively. As the photoactivity of parietin is essential for therapy, the quantum yield of PTN NPs and the in vitro release were assessed. The antiproliferative activity, the intracellular generation of reactive oxygen species, mitochondrial potential depolarization, and lysosomal membrane permeabilization were evaluated in triple-negative breast cancer cells (MDA-MB-231 cells). At the same time, confocal laser scanning microscopy (CLSM) and flow cytometry were used to investigate the cellular uptake profile. In addition, the chorioallantoic membrane (CAM) was employed to evaluate the antiangiogenic effect microscopically. The spherical monomodal PTN NPs show a quantum yield of 0.4. The biological assessment on MDA-MB-231 cells revealed that free PTN and PTN NPs inhibited cell proliferation with IC50 of 0.95 µM and 1.9 µM at 6 J/cm2, respectively, and this can be attributed to the intracellular uptake profile as proved by flow cytometry. Eventually, the CAM study illustrated that PTN NPs could reduce the number of angiogenic blood vessels and disrupt the vitality of xenografted tumors. In conclusion, PTN NPs are a promising anticancer strategy in vitro and might be a tool for fighting cancer in vivo.

A short screening tool identifying systemic barriers to distress screening in cancer care.

INTRODUCTION: International guidelines on cancer treatment recommend screening for early detection and treatment of distress. However, screening rates are insufficient. In the present study, a survey was developed to assess perceived systemic barriers to distress screening. METHODS: A three-step approach was used for the study. Based on qualitative content analysis of interviews and an expert panel, an initial survey with 53 questions on barriers to screening was designed. It was completed by 98 nurses in a large comprehensive cancer center in Switzerland. From this, a short version of the survey with 24 questions was derived using exploratory principal component analysis. This survey was completed by 150 nurses in four cancer centers in Switzerland. A confirmatory factor analysis was then performed on the shortened version, yielding a final set of 14 questions. RESULTS: The initial set of 53 questions was reduced to a set of 14 validated questions retaining 53% of the original variance. These 14 questions allow for an assessment within 2-3 min that identifies relevant barriers to distress screening from the perspective of those responsible for implementation of distress screening. Across several hospitals in Switzerland, the timing of the first distress screening, lack of capacity, patient and staff overload, and refusal of distressed patients to be referred to support services emerged as major problems. CONCLUSION: The validated 14 questions on barriers to screening cancer patients for distress enable clinicians and hospital administrators to quickly identify relevant issues and take action to improve screening programs.

How to Xenograft Cancer Cells on the Chorioallantoic Membrane of a Fertilized Hen's Egg and Its Visualization by PET/CT and MRI.

The chorioallantoic membrane (CAM) of fertilized hen's eggs represents a unique and alternative model for cancer research. The CAM model provides an optimal platform for xenografting cancer cell lines and studying essential key factors. Tumor size and growth as well as angiogenesis can be investigated to evaluate the response of therapies and strategies against cancer. Preclinical imaging represented by magnetic resonance imaging and positron emission tomography/computed tomography can generate detailed anatomical and functional information and reveal excellent metabolic sensitivity. In the following, a guideline is introduced in order to find a simplified entrance to the CAM model in combination with modern preclinical imaging techniques. Finally, the presented procedures are additionally completed by histological studies in the form of hematoxylin and eosin as well as immunohistochemical staining.

Steriod-associated psychiatric burden in cancer patients.

This study explores the role of steroid administration in identifying distressed or even mentally disordered cancer patients (so-called case finding). Charts of 12 298 cancer patients (4499 treated with prednisone equivalents) were analysed descriptively. A subset of 10 945 was further explored via latent class analysis (LCA). LCA avoids confounding by indication because it subgroups patients without prior preconceptions based on homogeneous expression of traits (i.e. the variables examined). LCA identified four subgroups: two subgroups with high dosages of prednisone equivalent (≥80 mg/day on average over all treatment days) and two with low dosages. The two subgroups with high average dosages had an increased likelihood of psychotropic drug administration, but only one was more likely to require 1:1 observation. In one subgroup, low dosages of prednisone equivlents correlated with a slightly increased probability for a psychiatric assessment and psychotropic drug administration. The subgroup least likely to receive steroid treatment was also the least likely to receive a psychiatric assessment and psychotropic drug administration. Descriptive statistics on age, sex, cumulative inpatient treatment, type of cancer, stage of cancer at first diagnosis, mental disorders, severe mental disorders and psychotropic drug administration (antidepressants, antipsychotics, benzodiazepines, anticonvulsants/mood stabilizers, opioids) are provided for patients receiving no, less and more than 80 mg of prednisone equivalent.

Early Impact of the COVID-19 Pandemic on Psycho-Oncological Support: A Latent Class Analysis.

INTRODUCTION: Research suggests a global shortfall of psycho-oncological assessment and care during the COVID-19 pandemic in addition to delayed diagnosis of cancer. The present study is the first to explore the effect of the pandemic on the provision of psycho-oncological care, stage of cancer at first diagnosis, and duration of hospitalizations. METHOD: Retrospective latent class analysis of 4,639 electronic patient files with all types, treatment types, and stages of cancer, 370 of which were treated during the pandemic prior to availability of vaccinations. DISCUSSION: Latent class analysis identified four subgroups based on differences in screening for distress, provision of psycho-oncological support (consultation with a psychiatrist or clinical psychologist), administration of psychotropic medication, use of 1:1 observation, stage of cancer at first diagnosis, and duration of hospitalizations. Yet, the pandemic had no effect on subgrouping. Thus, the COVID-19 pandemic had no effect on the provision of psycho-oncological support. CONCLUSION: Results are contrary to prior research. The efficiency and quality of procedures implemented to provide psycho-oncological support during and prior to the pandemic are critically reflected.

Clinically Significant Distress and Physical Problems Detected on a Distress Thermometer are Associated With Survival Among Lung Cancer Patients.

BACKGROUND: The distress thermometer is a well-established screening tool to detect clinically significant distress in cancer patients. It is often administered in combination with the problem list, differentiating further between various (e.g., physical and emotional) sources of distress. OBJECTIVE: The present study aimed to extend previous research on the association between distress and overall survival. A further exploratory analysis aimed to evaluate the predictive value of the problem list for overall survival. METHODS: Patients (n = 323) with newly diagnosed lung cancer were recruited from a large cancer center. Patients were split into 2 groups, those with (distress thermometer score ≥5) and those without significant distress. The overall survival time was illustrated by a Kaplan-Meier curve and compared with a log-rank test. Univariable Cox proportional hazard models were built to control the association of distress with overall survival for age, gender, disease stage, comorbidity, and their interaction terms. Multiple linear regression was used to investigate the association of the items from the problem list with survival time. RESULTS: Patients with significant distress had a shorter survival time than patients without significant distress (25 vs. 43 months). Regression analysis revealed more problems with both "bathing and dressing" and "eating," as well as absence of "diarrhea" and increased "nervousness," to negatively associated with the overall survival time. CONCLUSIONS: Our results show that estimation of the survival function using cancer-related distress is possible. However, when using Cox regression, distress shows no significant value for survival as a predictor. Moreover, our study did not reveal an interaction effect among disease stage, comorbidity, and distress. Overall, results suggest that physical and emotional problems that arise from lung cancer may be useful to identify patients at risk of poor prognosis (on the basis of Kaplan-Meier estimator).

Reading Wishes from the Lips: Cancer Patients' Need for Psycho-Oncological Support during Inpatient and Outpatient Treatment.

BACKGROUND: Psycho-oncological support (PO) is an effective measure to reduce distress and improve the quality of life in patients with cancer. Currently, there are only a few studies investigating the (expressed) wish for PO. The aim of this study was to evaluate the number of patients who request PO and to identify predictors for the wish for PO. METHODS: Data from 3063 cancer patients who had been diagnosed and treated at a Comprehensive Cancer Center between 2011 and 2019 were analyzed retrospectively. Potential predictors for the wish for PO were identified using logistic regression. As a novelty, a Back Propagation Neural Network (BPNN) was applied to establish a prediction model for the wish for PO. RESULTS: In total, 1752 patients (57.19%) had a distress score above the cut-off and 14.59% expressed the wish for PO. Patients' requests for pastoral care (OR = 13.1) and social services support (OR = 5.4) were the strongest predictors of the wish for PO. Patients of the female sex or who had a current psychiatric diagnosis, opioid treatment and malignant neoplasms of the skin and the hematopoietic system also predicted the wish for PO, while malignant neoplasms of digestive organs and older age negatively predicted the wish for PO. These nine significant predictors were used as input variables for the BPNN model. BPNN computations indicated that a three-layer network with eight neurons in the hidden layer is the most precise prediction model. DISCUSSION: Our results suggest that the identification of predictors for the wish for PO might foster PO referrals and help cancer patients reduce barriers to expressing their wish for PO. Furthermore, the final BPNN prediction model demonstrates a high level of discrimination and might be easily implemented in the hospital information system.

Severe mental illness in cancer is associated with disparities in psycho-oncological support.

Patients with both cancer and a severe mental illness (SMI) have a higher risk of advanced stage cancer at diagnosis and poorer survival in comparison to individuals with cancer alone. The present study explores if similar disparities exist in terms of psycho-oncological support. Latent class analysis (LCA) was used to group 10,945 patients with any type of cancer, of which 72 (0.7%) had been diagnosed with a SMI (ICD10-codes F20-F22, F24, F25, F28-F31, F32.3, F33.3), and 1056 (9.6%) with another mental disorder. Subgrouping was based on presence of SMI, other mental illnesses, stage of cancer at its first detection, screening for distress and receipt of information on psycho-oncology, consultation with a psychotherapist and/or psychiatrist, prescription of different psychotropic medication, and use of a patient care attendant. Five subgroups were identified. Patients with SMI were most likely to suffer from further mental comorbidities, to be prescribed antipsychotics, antidepressants, or mood stabilizers, and be in need of a patient care attendant. In comparison to patients without SMI, the larger one of 2 subgroups of patients with SMI had a low probability to be screened for distress and informed about psycho-oncological support services. A smaller subgroup of patients with SMI was probable to be diagnosed with an advanced stage of cancer. In subgroups without patients with mental disorders, screening for distress and offering psycho-oncological support seemed to be economized unless benzodiazepines or opioids were prescribed. Contrary to published evidence, distress screening and offering psycho-oncological support is neglected in patients with SMI unless an advanced stage of cancer is being diagnosed.

Towards identifying cancer patients at risk to miss out on psycho-oncological treatment via machine learning.

OBJECTIVE: In routine oncological treatment settings, psychological distress, including mental disorders, is overlooked in 30% to 50% of patients. High workload and a constant need to optimise time and costs require a quick and easy method to identify patients likely to miss out on psychological support. METHODS: Using machine learning, factors associated with no consultation with a clinical psychologist or psychiatrist were identified between 2011 and 2019 in 7,318 oncological patients in a large cancer treatment centre. Parameters were hierarchically ordered based on statistical relevance. Nested resampling and cross validation were performed to avoid overfitting. RESULTS: Patients were least likely to receive psycho-oncological (i.e., psychiatric/psychotherapeutic) treatment when they were not formally screened for distress, had inpatient treatment for less than 28 days, had no psychiatric diagnosis, were aged 65 or older, had skin cancer or were not being discussed in a tumour board. The final validated model was optimised to maximise sensitivity at 85.9% and achieved an area under the curve (AUC) of 0.75, a balanced accuracy of 68.5% and specificity of 51.2%. CONCLUSION: Beyond conventional screening tools, results might contribute to identify patients at risk to be neglected in terms of referral to psycho-oncology within routine oncological care.

Distinct psycho-oncological support inclinations and needs in patients with cancer: A large sample latent class analysis approach.

BACKGROUND: In patients with cancer, the routine recording of distress symptoms has been widely established in recent years. Psycho-oncological support has proven to reduce distress and increase quality of life. Despite high levels of distress as well as physical and emotional challenges in patients with cancer, a significant proportion forgoes psycho-oncological services. METHODS: A cross-sectional retrospective evaluation was carried out. Latent class analysis was used to examine the relationship between distress, physical and emotional challenges, and desire for psycho-oncological services in 2191 patients with cancer. RESULTS: Latent class analysis revealed four homogeneous subgroups: a) patients with high distress, high physical and low emotional challenges and no desire for psycho-oncology, b) patients with high distress, low physical and high emotional challenges and no desire for psycho-oncology, c) patients with high distress, high physical and emotional challenges and a desire for psycho-oncology, d) patients with low distress, low physical and emotional challenges and no desire for psycho-oncology. CONCLUSION: The identification of these subgroups of patients with cancer is useful for health care providers in order to focus their efforts in patients with cancer. It might contribute to a more tailored treatment offer for specific subgroups whose needs have so far been insufficiently met.

Uncovering Barriers to Screening for Distress in Patients With Cancer via Machine Learning.

BACKGROUND: Psychologic distress and manifest mental disorders are overlooked in 30-50% of patients with cancer. Accordingly, international cancer treatment guidelines recommend routine screening for distress in order to provide psychologic support to those in need. Yet, institutional and patient-related factors continue to hinder implementation. OBJECTIVE: This study aims to investigate factors, which are associated with no screening for distress in patients with cancer. METHODS: Using machine learning, factors associated with lack of distress screening were explored in 6491 patients with cancer between 2011 and 2019 at a large cancer treatment center. Parameters were hierarchically ordered based on statistical relevance. Nested resampling and cross validation were performed to avoid overfitting and to comply with assumptions for machine learning approaches. RESULTS: Patients unlikely to be screened were not discussed at a tumor board, had inpatient treatment of less than 28 days, did not consult with a psychiatrist or clinical psychologist, had no (primary) nervous system cancer, no head and neck cancer, and did have breast or skin cancer. The final validated model was optimized to maximize sensitivity at 83.9%, and achieved a balanced accuracy of 68.9, area under the curve of 0.80, and specificity of 53.9%. CONCLUSION: Findings of this study may be relevant to stakeholders at both a clinical and institutional level in order to optimize distress screening rates.

Mental disorders, length of hospitalization, and psychopharmacy-New approaches to identify barriers to psychological support for patients with cancer.

BACKGROUND: Despite abundant evidence that emotional distress is frequent in cancer patients and associated with adverse health outcomes, distress screening rates and adequate referrals to psychological support programs among those in need are insufficient in many cancer centers. We therefore aimed to analyze patient- and treatment-related barriers to distress screening and referrals to psychological support as a mandatory component of best-practice cancer care. METHOD: In the present explorative study, latent class analysis was used to identify homogeneous subgroups among 4837 patients diagnosed with cancer between 2011 and 2019. RESULTS: Four subgroups were identified. Patients with a mental disorder and psychopharmacology were least probable to be screened for distress. Together with patients aged 65 or older and male patients, they were also less likely to receive psychological support. Patients hospitalized for 28 days or longer were most likely to be both screened and to receive psychological support. CONCLUSIONS: Clinicians and researchers are recommended not neglect patients with mental disorders and psychopharmacological treatment as well as male and elderly patients when screening for distress and providing access to psychological support.

The chorioallantoic membrane as a bio-barrier model for the evaluation of nanoscale drug delivery systems for tumour therapy.

In 2010, the European Parliament and the European Union adopted a directive on the protection of animals used for scientific purposes. The directive aims to protect animals in scientific research, with the final goal of complete replacement of procedures on live animals for scientific and educational purposes as soon as it is scientifically viable. Furthermore, the directive announces the implementation of the 3Rs principle: "When choosing methods, the principles of replacement, reduction and refinement should be implemented through a strict hierarchy of the requirement to use alternative methods." The visibility, accessibility, and the rapid growth of the chorioallantoic membrane (CAM) offers a clear advantage for various manipulations and for the simulation of different Bio-Barriers according to the 3R principle. The extensive vascularisation on the CAM provides an excellent substrate for the cultivation of tumour cells or tumour xenografts which could be used for the therapeutic evaluation of nanoscale drug delivery systems. The tumour can be targeted either by topical application, intratumoural injection or i.v. injection. Different application sites and biological barriers can be examined within a single model.

In Ovo Testing Method for Inhalants on a Chorio-Allantoic Membrane.

Solid tumors and metastasis rely on angiogenesis for sufficient supply as they grow, making antiangiogenic treatment a promising option in the combat of cancer. Testing of inhalants on the chorio-allantoic membrane offers a simple but precise method to assess the impact on angiogenesis. The in ovo testing method can be used to directly determine the effect of inhaled formulations solely or in the context of photodynamic therapy. In this study curcumin liposomes served as a model for testing of pulmonary application and revealed an excellent antiangiogenetic effect. This efficacy of a model inhalant illustrates the suitability of the method.

Spray-Dried Nanoparticle-in-Microparticle Delivery Systems (NiMDS) for Gene Delivery, Comprising Polyethylenimine (PEI)-Based Nanoparticles in a Poly(Vinyl Alcohol) Matrix.

Nucleic acid-based therapies rely on efficient formulations for nucleic acid protection and delivery. As nonviral strategies, polymeric and lipid-based nanoparticles have been introduced; however, biological efficacy and biocompatibility as well as poor storage properties due to colloidal instability and their unavailability as ready-to-use systems are still major issues. Polyethylenimine is the most widely explored and promising candidate for gene delivery. Polyethylenimine-based polyplexes and their combination with liposomes, lipopolyplexes, are efficient for DNA or siRNA delivery in vitro and in vivo. In this study, a highly potent spray-dried nanoparticle-in-microparticle delivery system is presented for the encapsulation of polyethylenimine-based polyplexes and lipopolyplexes into poly(vinyl alcohol) microparticles, without requiring additional stabilizing agents. This easy-to-handle gene delivery device allows prolonged nanoparticle storage and protection at ambient temperature. Biological analyses reveal further advantages regarding profoundly reduced cytotoxicity and enhanced transfection efficacies of polyethylenimine-based nanoparticles from the nanoparticle-in-microparticle delivery system over their freshly prepared counterparts, as determined in various cell lines. Importantly, this nanoparticle-in-microparticle delivery system is demonstrated as ready-to-use dry powder to be an efficient device for the inhalative delivery of polyethylenimine-based lipopolyplexes in vivo, as shown by transgene expression in mice after only one administration.

Microparticulate poly(vinyl alcohol) hydrogel formulations for embedding and controlled release of polyethylenimine (PEI)-based nanoparticles.

Nucleic acid-based therapeutics offer enormous potential in the treatment of various pathologies. For DNA or RNA delivery, nanoparticle systems based on lipids or polymers have been developed. However, colloidal instability in solution, poor storage properties especially as dry powder and little stability against an aggressive environment, e.g. after oral application, are major issues. Furthermore, there is an urgent need for sustained release systems that allow for fine-tuned, long-term temporal and spatial nanoparticle release. In this paper, we describe the embedding of polymeric nanoparticles for gene delivery, namely polyethylenimine (PEI)-based polyplexes and their corresponding liposome-modified analogues (lipopolyplexes), into microparticulate poly (vinyl alcohol) (PVA) hydrogels. Various parameters are modified, and major differences are found. PVA is explored with two different molecular weights and at different concentrations, furthermore different emulsifiers and acetone for extraction are employed, and the protocol is performed with or without repetitive freeze/thaw cycles for physical PVA crosslinking. We thereby establish Nanoparticles-in-Microparticle Delivery Systems (NiMDS) that are extensively characterized and shown to allow prolonged storage as easy-to-handle formulation (dry powder) without loss of nanoparticle activity. Unexpectedly, the nanoparticles' PVA encapsulation/release alters important physicochemical nanoparticle properties and biological activities in a favourable way. Furthermore, we also demonstrate the nanoparticle release to be dependent on the microstructure of the PVA matrix, which is determined by the degree of physical crosslinking through a defined number of freeze/thaw cycles. We show that these defined physically crosslinked PVA hydrogels thus represent sustained release devices for fine-tuned, long-term nanoparticle release in possible therapeutic applications. STATEMENT OF SIGNIFICANCE: The present paper for the first time describes the embedding of polymeric PEI-based polyplexes and lipopolyplexes into poly(vinyl alcohol) (PVA) hydrogels, to establish novel Nanoparticles-in-Microparticle Delivery Systems (NiMDS). Through modification of various parameters including different PVA molecular weights and concentrations, different emulsifiers and defined numbers of freeze-thaw cycles for physical PVA crosslinking, sustained release devices are also obtained. Beyond favourable alterations of important physicochemical/biological nanoparticle properties and the possibility for prolonged storage as easy-to-handle formulation (dry powder), we show that these NiMDS also allow the tailormade, fine-tuned, long-term release of fully active nanoparticles in possible therapeutic applications.