I've accomplished the zoom in using images. And I've used this:
Code:
Public Sub ZoomImage(ByRef ZoomValue As Int32)
    Dim original As Image

    'Get our original image
    original = PictureBox1.Image

    'Create a new image based on the zoom parameters we require
    Dim zoomImage As New Bitmap(original,   (Convert.ToInt32(original.Width  * ZoomValue) / 100), (Convert.ToInt32(original.Height * ZoomValue  / 100)))

    'Create a new graphics object based on the new image
    Dim converted As Graphics = Graphics.FromImage(zoomImage)

    'Clean up the image
    converted.InterpolationMode = InterpolationMode.HighQualityBicubic

    'Clear out the original image
    PictureBox1.Image = Nothing

    'Display the new "zoomed" image
    PictureBox1.Image = zoomImage
End Sub
The problem is that I've shape controls (rectangle and lines) in the picture box and I want to zoom in / zoom out them. I've tried different codes, but at the moment I'm still searching the solution.