Cellular Uptake Of Particles Research Articles

Gold nanoparticles coated with collagen-I and their wound healing activity in human skin fibroblast cells

The slow wound healing process has become a major health problem. Gold nanoparticles (AuNPs) have been used in various biomedical applications because of their unique properties. Type I collagen (Collagen-I) is a protein and be the most abundant type of collagen. This type of collagen can help the surrounding structure to maintain its rigidity. In this study, we stabilized the surface of AuNPs using Collagen-I (Collagen-I@AuNPs) and investigated the effect of Collagen-I@AuNPs on wound healing. The evaluation of inflammatory cytokine secretion, which were interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-α), was performed. We found that Collagen-I@AuNPs reduced the levels of IL-6 and TNF-α in scratched human skin fibroblast (HSF) cells. Furthermore, Collagen-I@AuNPs induced the expression of basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF), which are key growth factors involved in wound healing. This results in enhanced wound closure. In addition, Collagen-I@AuNPs were not toxic to HSF cells and facilitated the cellular uptake of particles inside HSF cells. Therefore, Collagen-I@AuNPs is a promising candidate for wound healing enhancement.

Substrate Stiffness and Particle Properties Influence Cellular Uptake of Nanoparticles and Viruses from the Ventral Side

AbstractIt is a long‐standing challenge to exploit cellular uptake mechanisms to deliver desired cargo into cells, for example, specific drugs or gene editing techniques. This study introduces a bioinspired material approach where nanoparticles are presented at the ventral side of cells adhering to engineered extracellular matrices. The effect of matrix stiffness on cell adhesion and mechanics, as well as on particle internalization by clathrin‐mediated endocytosis (CME), is investigated for varying particle size and surface functionalization. The results presented here show that substrate stiffness affects both cell adhesion and particle internalization, with softer substrates promoting higher levels of particle uptake. However, the activation of the CME pathway, either mechanically by particle size or functionally by receptor binding, regulates the sensitivity of cellular particle uptake to matrix stiffness. Finally, adeno‐associated viruses as the leading platform for therapeutic gene delivery are used as model cargo to showcase the importance of considering multiple components when designing delivery systems. These findings indicate that particle uptake is a multifaceted process that can be improved by the appropriate combination of extracellular environment mechanics and cargo properties.

Evaluation of the cellular effects of silica particles used for dermal application

ABSTRACT The cellular effects of 5 types of spherical amorphous silica particles whose particle size were 4.2–12.8 μm for cosmetic use and two types of crystalline silica whose particle size were 2.4 and 7.1 μm particles for industrial use were examined. These silica particles were applied to HaCaT human keratinocytes for 24 hr. Crystalline silica enhanced IL-8 and IL-6 expression and caused cell membrane damage. Crystalline silica also enhanced HO-1 gene expression; however, the level of intracellular ROS did not change. Compared with crystalline silica, the cellular effects of the spherical silica employed in this study were minor. Cellular uptake of particles was observed for all of silica particle types. Cellular uptake of crystalline silica was observed 1 hr after exposure, and internalized silica particles were present in the cytoplasm. When HaCaT cells were exposed to crystalline silica for 1 hr and incubated for 23 hr in culture medium without silica particles, IL-8 expression was still detected. In addition, silica particles exerted negligible effects using a 3D skin tissue model. Thus, the following conclusions may be drawn. (1) cellular effects exerted by spherical silica are less compared to crystalline silica. (2) phagocytosis of particles is an important first step in the cellular effects of silica particles. (3) spherical silica particles might exert little, if any, effect on healthy skin attributed to no apparent cellular uptake.

Impact of titanium dioxide particle size on macrophage production of intracellular reactive oxygen species

ObjectivesThe aim of this study was to investigate the response of THP-1 monocyte-derived macrophages following exposure to titanium dioxide nanoparticles (TiO2 NPs) and microparticles (TiO2 MPs) in an in vitro system. DesignTHP-1 monocytes were maintained in RPMI medium and transformed into M0 macrophages using Phorbol 12-myristate 13-acetate (PMA). TiO2 particle size characterization was performed using scanning electron microscopy (SEM) and dynamic light scattering (DLS) technology. A viability study using an XTT assay was performed by treating THP-1-derived macrophages with TiO2 NPs (<100 nm) and TiO2 MPs (<5 μm) at concentrations ranging from 100, 50, 25, 12.5, 6.25 and 3.125 μg/mL. Macrophages were then treated with three different concentrations of NPs and MPs (5, 20 or 100 μg/mL) for 24 h, and ROS production and TiO2 particle cellular uptake were measured using ROS assays and flow cytometry, respectively. ResultsThere was no significant change in the viability of THP-1 monocytes after treatment with TiO2 NPs and MPs. The uptake of both particles was confirmed and showed an increase in ROS generation, and the MPs produced more ROS than NPs. The increase in ROS generation with NPs was concentration-dependent. ConclusionUptake of TiO2 NPs and MPs in macrophages at subcytotoxic levels generate ROS in a size- and dose-dependent manner.

Surface Stabilization Affects Toxicity of Silver Nanoparticles in Human Peripheral Blood Mononuclear Cells.

Silver nanoparticles (AgNPs) are one of the most investigated metal-based nanomaterials. Their biocidal activity boosted their application in both diagnostic and therapeutic medical systems. It is therefore crucial to provide sound evidences for human-related safety of AgNPs. This study aimed to enhance scientific knowledge with regard to biomedical safety of AgNPs by investigating how their different surface properties affect human immune system. Methods: preparation, characterization and stability evaluation was performed for four differently coated AgNPs encompassing neutral, positive and negative agents used for their surface stabilization. Safety aspects were evaluated by testing interaction of AgNPs with fresh human peripheral blood mononuclear cells (hPBMC) by means of particle cellular uptake and their ability to trigger cell death, apoptosis and DNA damages through induction of oxidative stress and damages of mitochondrial membrane. Results: all tested AgNPs altered morphology of freshly isolated hPBMC inducing apoptosis and cell death in a dose- and time-dependent manner. Highest toxicity was observed for positively-charged and protein-coated AgNPs. Cellular uptake of AgNPs was also dose-dependently increased and highest for positively charged AgNPs. Intracellularly, AgNPs induced production of reactive oxygen species (ROS) and damaged mitochondrial membrane. Depending on the dose, all AgNPs exhibited genotoxic potential. Conclusions: this study provides systematic and comprehensive data showing how differently functionalized AgNPs may affect the human immune system. Presented results are a valuable scientific contribution to safety assessment of nanosilver-based blood-contacting medical products.

Cellular Uptake of Active Particles.

Active particles are widely recognized to potentially revolutionize technologies in numerous biomedical applications. However, the physical origin behind cellular uptake of these particles in the nonequilibrium state remains scarcely understood. Here we combine Brownian dynamics simulation as well as theoretical analysis to provide the criterion for cellular uptake of active particles, related to various physical attributes. Upon enhancing the activity, the uptake efficiency for the active particles with tilted orientation is examined to be nonmonotonic, in stark contrast to the monotonic dependence for active particles orientated normally to the membrane. This can be attributed to the interplay between membrane adhesion energy and kinetic energy of active particles, resulting in unique kinetic pathways. Furthermore, a theoretical model that captures the essential physics of the cellular endocytosis process is developed to reproduce this nonmonotonic feature. The results are of immediate interest to understand and tune activity-mediated cellular interaction and internalization of such emerging colloids.

Cytotoxic and genotoxic potential of respirable fraction of composite dust on human bronchial cells

ObjectiveTo determine the cytotoxic and genotoxic potential of the respirable fraction of composite dust (<4 μm) on human bronchial epithelial cells. MethodsComposite sticks of three commercial dental composites (Filtek Supreme XTE, Grandio, Transbond XT) were ground in an enclosed plexiglass chamber with a rough dental bur (grain-size 100 μm) and the generated airborne respirable dust was collected in a personal cyclone on a teflon filter (pore size 5 μm). Immediately after particle collection, the dust was quantified gravimetrically and the particles were suspended in cell culturing medium. Next, human bronchial epithelial cells (16HBE14o-) were exposed to the suspensions (3 μg/ml–400 μg/ml). After 24 h, cell viability (WST-1 assay) and membrane integrity (LDH assay) were evaluated. Furthermore, the genotoxic effect of a sub-cytotoxic concentration (50 μg/ml) of composite dust was evaluated by the comet assay after 3 h exposure and cell cycle disturbances were analyzed by flow cytometry. Cellular uptake of particles was evaluated by transmission electronic microscope (TEM). ResultsFor all three tested composite materials, a decrease in metabolic activity of 10–35% was observed when the cells were exposed to the highest concentrations (100 μg/ml–400 μg/ml). Toxicity was partially linked to membrane disruption especially after 72 h exposure. All tested composites provoked a mild genotoxic effect after short-term exposure compared to the control groups. TEM revealed that respirable particles of all tested composites were taken up by the cells. SignificanceThe respirable fraction of composite dust only showed cytotoxic effects at the highest concentrations, whereas mild genotoxicity was observed after exposure to a sub-cytotoxic concentration.

Enrichment of Native Lipoprotein Particles with microRNA and Subsequent Determination of Their Absolute/Relative microRNA Content and Their Cellular Transfer Rate.

Lipoprotein particles are predominately transporters of lipids and cholesterol in the bloodstream. Furthermore, they contain small amounts of strands of noncoding microRNA (miRNA). In general, miRNA alters the protein expression profile due to interactions with messenger-RNA (mRNA). Thus, knowledge of the relative and absolute miRNA content of lipoprotein particles is essential to estimate the biological effect of cellular particle uptake. Here, a quantitative real-time polymerase chain reaction (qPCR)-based protocol is presented to determine the absolute miRNA content of lipoprotein particles-exemplified shown for native and miRNA-enriched lipoprotein particles. The relative miRNA content is quantified using multiwell microfluidic array cards. Furthermore, this protocol allows scientists to estimate the cellular miRNA and, thus, the lipoprotein particle uptake rate. A significant increase of the cellular miRNA level is observable when using high-density lipoprotein (HDL) particles artificially loaded with miRNA, whereas incubation with native HDL particles yields no significant effect due to their rather low miRNA content. In contrast, the cellular uptake of low-density lipoprotein (LDL) particles-neither with native miRNA nor artificially loaded with it-did not alter the cellular miRNA level.

Quantitative Analysis of the Correlation between Cell Size and Cellular Uptake of Particles

The size of a cell is central to many functions, including cellular communication and exchange of materials with the environment. This modeling and experimental study focused on understanding how the size of a cell determines its ability to uptake nanometer-scale extracellular materials from the environment. Several mechanisms in the cell plasma membrane mediate cellular uptake of nutrients, biomolecules, and particles. These mechanisms involve recognition and internalization of the extracellular molecules via endocytic components, such as clathrin-coated pits, vacuoles, and micropinocytic vesicles. Because the demand for an external resource could be different for cells of different sizes, the collective actions of these various endocytic routes should also vary based on the cell size. Here, using a reaction-diffusion model, we analyze single-cell data to interrogate the one/one mapping between the size of the MDA-MB 231 breast cancer cells and their ability to uptake nanoparticles. Our analysis indicates that under both reaction- and diffusion-controlled regimes, cellular uptake follows a linear relationship with the cell radius. Furthermore, this linear dependency is insensitive to particle size variation within 20–200 nm range. This result is counterintuitive because the general perception is that cellular uptake is proportional to the cell volume (mass) or surface area and hence follow a cubic or square relationship with the cell radius. A further analysis using our model reveals a potential mechanism underlying this linear relationship.

Radiosensitization of breast cancer cells using AS1411 aptamer-conjugated gold nanoparticles

Introduction: A main choice for cancer treatment is radiotherapy. But, the radiotherapy disadvantage is damages caused by radiation given to normal tissues/organs surrounding cancer. One way to avoid this is via increasing radiosensitization of cancer cells. Gold nanoparticles (GNPs) have shown sensitizing effect on cancer cells by enhancing their absorbed dose. Unlike earlier delivery techniques developed for nanotherapeutics, active targeting can achieve specific effect and higher uptake of GNPs in tumors while leave healthy cells untouched and consequently improve the therapeutic index. To achieve active targeting, GNPs should be equipped with functional ligands which can recognize and adhere to the receptors of cancer cells. Aptamers are small DNA-molecule/RNA-fragments with high specificity and affinity towards target molecules. AS1411 aptamer can specifically bind to over-expressed nucleolin on the membrane of tumor cells including breast cancer. This aptamer is capable to enter cancer cells through specific ligand–receptor interaction. Greater uptake of GNPs by cells may induce increased radiation effects. Cancer stem cells are a small population of cells within a tumor capable for self-renewal and differentiation into various cell types. Materials and Methods: We hypothesized that conjugation of GNPs with AS1411 (AS1411/GNPs) could increase GNPs-mediated radiosensitization in breast cancer cells. We hypothesized that AS1411/GNPs would radiosensitize breast cancer stem/progenitor cells grown to three- dimensional (3D) mammospheres. Cytotoxicity studies of the GNPs and AS1411/GNPs were done on two different cancer cell lines of MCF-7 and MDA-MB-231 with MTT assay. Atomic absorption spectroscopy (AAS) confirmed the cellular uptake of particles. Radiosensitizing effect of GNPs and AS1411/GNPs on MDA-MB 231 and MCF- 7 cells assessed by clonogenic assay. Results: Clonogenic survival data revealed that AS1411/GNPs at 12.5 mg/L results in radiosensitization of breast cancer cells. Mammosphere of MCF-7 was more resistant than their monolayer counterparts. Conclusion: The combination of the sensitizing GNPs with the AS14411 aptamer can be regarded for improved treatment of breast cancer cells especially for the mammosphere MCF-7 cancer cells mimicking cancerous tumors.

Physicochemical properties of particulate vaccine adjuvants: their pivotal role in modulating immune responses

Vaccine adjuvants enhance immunogenic responses of antigens and increase potency of vaccines. Physicochemical properties of particulate vaccine adjuvants namely, particle size, surface charge, hydrophobicity, shape and composition play an important role to determine their activity and potency. Various studies have been done using different types of particulate vaccine adjuvants to correlate their physicochemical properties with immune responses. Generally, change in particle size does not show any trend in modulation of immunogenicity, however, it directly influences on cellular uptake of particles, leading to alteration of cytokine profile and induction of Th1 and/or Th2 responses. Usually, positively charged adjuvant particles undergo higher cellular uptake than negatively charged particles and hydrophobic particles undergo cellular uptake more efficiently than hydrophilic particles. Furthermore, shape and composition of adjuvant particles also influence on immune responses. This review gives an insight into the impact of particle size, surface charge, hydrophobicity, shape and composition of particulate vaccine adjuvants in modulating immune responses.

PEG coated and doxorubicin loaded multimodal Gadolinium oxide nanoparticles for simultaneous drug delivery and imaging applications

We report water-in-oil microemulsion mediated synthesis of PEG11Polyethylene glycol coated Gd2O3 NPs22Nanoparticles loaded with fluorescent anti-cancer drug dox33Doxorubicin for synchronous drug delivery, optical and MR44Magnetic resonance imaging applications. These PEG covered Gd2O3 NPs loaded with dox (Gd-PEG-dox NPs) were found to possess spherical morphology with 13nm size as measured from TEM and the hydrodynamic diameter comes out to be 37nm as determined from DLS. Fluorescence spectra and fluorescence microscopy images confirmed optical activity of the NPs. The paramagnetic nature of NPs was affirmed by NMR line broadening effect on the spectrum of surrounding water protons. Therefore, these particles can be efficiently used as CA55Contrast agent in MR imaging. In vitro analysis showed significant cellular uptake of particles by A-549 cells. A pH dependent drug release pattern was observed for the NPs. Cell viability assay performed on A-549, PANC-1 and U-87 cancerous cell lines revealed that Gd-PEG-dox NPs are cytotoxic. On the basis of these observations, it can be concluded that these multi-modal paramagnetic NPs promise potential cancer therapy along with optical and MR imaging applications.

Tuning the Mechanical Properties of Hydrogel Core-Shell Particles by Inwards Interweaving Self-Assembly.

Mechanical properties of hydrogel particles are of importance for their interactions with cells or tissue, apart from their relevance to other applications. While so far the majority of works aiming at tuning particle mechanics relied on chemical cross-linking, we report a novel approach using inwards interweaving self-assembly of poly(allylamine) (PA) and poly(styrenesulfonic acid) (PSSA) on agarose gel beads. Using this technique, shell thicknesses up to tens of micrometers can be achieved from single-polymer incubations and accurately controlled by varying the polymer concentration or incubation period. We quantified the changes in mechanical properties of hydrogel core-shell particles. The effective elastic modulus of core-shell particles was determined from force spectroscopy measurements using the colloidal probe-AFM (CP-AFM) technique. By varying the shell thickness between 10 and 24 μm, the elastic modulus of particles can be tuned in the range of 10-190 kPa and further increased by increasing the layer number. Through fluorescence quantitative measurements, the polymeric shell density was found to increase together with shell thickness and layer number, hence establishing a positive correlation between elastic modulus and shell density of core-shell particles. This is a valuable method for constructing multidensity or single-density shells of tunable thickness and is particularly important in mechanobiology as studies have reported enhanced cellular uptake of particles in the low-kilopascal range (<140 kPa). We anticipate that our results will provide the first steps toward the rational design of core-shell particles for the separation of biomolecules or systemic study of stiffness-dependent cellular uptake.

Evaluation of polymeric nanoparticle formulations by effective imaging and quantitation of cellular uptake for controlled delivery of doxorubicin.

Various polymeric nanoparticles have been extensively engineered for applications in controlled drug release delivery in the last decades. Currently, there is a great demand to develop a strategy to qualitatively and quantitatively evaluate these polymeric nanoparticle formulations for producing innovative delivery systems. In this work, a screening platform is developed using luminescent quantum dots as drug model and imaging label to evaluate nanoparticle formulations incorporating either hydrophilic or hydrophobic drugs and imaging agents. It is validated that there is no influence of the incorporated entities on the cellular uptake profile. The use of quantum dots enables efficient detection and precise quantitation of cellular uptake of particles which occupy 25% of the cell volume. The correlation of quantum dot- and doxorubicin-incorporated nanoparticles is useful to develop an evaluation platform for nanoparticle formulations through imaging and quantitation. This platform is also used to observe the surface properties effect of other polymers such as chitosan and poly(ethylene) glycol on the cellular interaction and uptake. Moreover, quantum dots can be used to study microparticle theranostic delivery formulations by deliberately incorporating as visible ring surrounding the microparticles for their easy identifying and tracing in diagnostic and chemotherapeutic applications.

Nanomaterial-mediated photothermal cancer treatment: the pivotal role of cellular uptake on photothermal therapeutic efficacy

Nanomaterial-mediated photothermal therapy (PTT) is expected to play a vital role in the treatment of malignant cells. In this study, Au nanorods (NRs) and silica@Au nanoshells (NSs) were synthesized and characterized to demonstrate the PTT efficiency of two nanomaterials for A549 and HeLa cancer cells under different conditions. To determine the impact of particle uptake and photothermal conversion efficiency on PTT efficiency, the threshold loading particle dosages, cellular particle uptake threshold, and threshold average particle dosages of both nanomaterials were monitored for both types of cancer cells. Both receptor-mediated endocytosis and non-specific endocytosis contributed a certain level of nanomaterial particles to the threshold particle dosages. Cellular uptake experiments were conducted at 4 °C to appraise the contribution of receptor-mediated endocytosis, and chlorpromazine-treated cellular uptake experiments were used to evaluate the contribution of non-specific endocytosis. It is hypothesized that PTT efficiency depends on the threshold average particle dosage and the threshold average particle dosage is the sum of receptor-mediated endocytosis and non-specific endocytosis. This concept can serve as a reference for the use of PTT in animal tests and clinical trials. The challenge of effective PTT efficiency in the use of in vivo and clinical tests was also discussed according to our experimental results.

Spray-Dried Polyelectrolyte Microparticles in Oral Antigen Delivery: Stability, Biocompatibility, and Cellular Uptake

During the past decade, extensive research has undeniably improved the formulation and delivery of oral vaccines. Nevertheless, several factors, such as the harsh gastrointestinal environment together with tolerance induction to exogenous antigens, have thus far impeded the optimal effectiveness and clinical application of oral delivery systems. The current study encompasses an initial evaluation of the stability, biocompatibility, and cellular uptake of two promising candidate systems for oral antigen delivery, that is, calcium carbonate- (CP) and mannitol-templated (MP) porous microspheres. Both spray-dried formulations were efficiently internalized by human intestinal epithelial cells (Caco-2 and HT-29) and degraded into phagolysosomal intracellular compartments. In addition, cellular particle uptake and processing significantly up-regulated the expression of (HLA) class-II and costimulatory molecules on intestinal epithelial cells. Even though the high surface-area-to-volume ratio of the microspheres was expected to favor protease access, antigen release was remarkably limited in simulated intestinal fluid and was even absent under gastric conditions. Finally, neither CP nor MP exerted cytotoxicity upon prolonged in vitro incubation with high antigen concentration. Altogether, these data support the potential of CP and MP for oral antigen delivery and motivate the further development of these promising carrier systems in in vivo studies.

Noncovalent functionalization of mesoporous silica nanoparticles with amphiphilic peptides.

The surface of mesoporous silica nanoparticles (MSNs) has been modified for enhancing their cellular uptake, cell targeting, bioimaging, and controlled drug release. For this purpose, covalent anchorage on the silica surface was predominantly exploited with a wide range of bioactive molecules. Here, we describe a facile self-assembly method to prepare a hybrid peptide silica system composed of octyl-modified mesoporous silica nanoparticles (MSNs) and peptide amphiphiles (PAs). The hydrophobic organosilane surface of mesoporous silica was coated with amphiphilic peptide molecules. The peptide functionalized particles exhibited good cyto-compatibility with vascular smooth muscle and vascular endothelial cells. The peptide coating also improved the cellular uptake of particles up to 6.3 fold, which is promising for the development of highly efficient MSN based theranostic agents.

Influence of Spacer Length on the Cellular Uptake of Polymeric Nanoparticles

Nanotechnology is finding ever increasing application in the life science arena where nanoparticles can be used to deliver cargoes in cells. However, a clear understanding of the relationship between the chemical properties of the particle and its uptake efficiency is lacking. Herein, the effects on particle cellular uptake following modification with a variety of spacers, all bearing a positive charge, but differing in length, and the influence on formation of the protein corona are investigated. Although no significant differences in the composition of the protein corona are detected, the spacer length influences the cellular uptake of the nanoparticles. These findings will allow the target-orientated functionalisation of particles to increase the specificity of cellular uptake.

Preparation of Eudragit L 100-55 enteric nanoparticles by a novel emulsion diffusion method

In this study, a novel emulsion diffusion method was used to prepare enteric Eudragit L100-55 nanoparticles by ultrasonic dispersion and diffusion solidification. Omeprazole was selected as the model drug. The prepared nanoparticles were in spherical shape and exhibited negative zeta potential. The Fourier transform infrared spectroscopy results indicated that no molecular interaction occurred between the drug molecule and polymer chain. In addition, the nanoparticles showed a strong pH-sensitive release in vitro. A mild cytotoxicity of nanoparticle was observed in the subsequent studies, and the particle cellular uptake study showed that the nanoparticles could be taken up by Caco-2 cells after 0.5h incubation. Our results indicated that the enteric Eudragit L 100-55 nanoparticle could be synthesized successfully via this ultrasonic solidification method, which also could be applied to prepare other pH-sensitive polymer nanoparticles.

Methoxy poly(ethylene glycol)-block-polycaprolactone copolymer: formulation and optimization by experimental design; determination of diblock molar mass by multivariate regression analysis of 1H NMR spectra

Recently, there was much attraction in amphiphilic block copolymers composed of methoxy poly(ethylene glycol) (MePEG) and biodegradable polyesters such as poly(caprolactone) (PCL). This copolymer significantly has applications in drug delivery systems. According to literature reports, efficiency of drug delivery and particle cellular uptake could be affected by many characteristics, such as particle size, different compositions of the particles, surface properties, different cell lines and cell densities, temperature. Hu et al. showed that the particle size is the key factor to determine the cellular uptake efficiency and it is found that the composition and molar mass of the copolymers are influential on the particle size. The present paper firstly discusses response surface methodology (RSM) as an efficient system for building a mathematical model and optimization of the apparent molar mass (Mn) by size-exclusion chromatography (SEC) (Y1) and nuclear magnetic resonance (1H NMR) (Y2). In this work, RSM is used to optimize the physical and chemical variables such as time, temperature, MePEG/CL and amount of Sn(Oct)2. A 24 small factorial central composite design (CCD) was employed. After evaluation of experimental results, a 2F1 model was found to be fit for Y1 response (SEC) and quadratic model for Y2 (NMR) without any requirement of power transformation. The selection of model was done on basis of high adjusted R2 value and lowered p-value for each model in individual analysis of each response. Through desirability analysis, it was found that SEC has a good precision/repeatability but a generally poor accuracy/reproducibility in determination of Mn. NMR is not suitable for determination of Mn for high molar mass PEG–PCL copolymers. Thus, the information that can be derived from NMR spectra is restricted because of broad and overlapping signals, poor solubility of polymers or non-availability of suitable solvents. NMR coupled with partial least squares (PLS) regression is applied to determine the Mn of MePEC in the present study. A PLS regression model with a coefficient of determination (R2) of 0.8444 and root-mean-square error of cross validation (RMSECV) of 0.5625 was obtained in the spectral range δ 0.28–7.28 ppm. The results obtained in this study indicate that 1H NMR spectroscopy can be used as an easy, rapid and novel tool to quantitatively predict the Mn of MePEC.